ClimaBulletin

Illinois · Annual

Year 2025

Final Issued 2026-10-21 · version 1 · Baseline 1991-2020 · next update 2027-01-10

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1 Key messages and climate synopsis

  • Statewide mean temperature of 12.1 °C (+0.6 °C relative to 1991–2020): the 10th warmest year in the 1979–2025 series (tied with 1991, 2005, 2007).
  • Statewide precipitation of 836.7 mm, 81% of normal: the 5th driest year in the 1979–2025 series.
  • The highest maximum temperature at GHCN stations was 37.8 °C at Flora on 15 September.
  • The largest 24-hour rainfall at GHCN stations was 152.4 mm at Shabbona 3S on 19 August.
  • 2 station records were broken (stations with at least 20 years of data).
  • Statewide heat waves: 6; cold waves: 4.
  • U.S. Drought Monitor: 71% of the state in drought (D1–D4) on 30 December 2025 (+50 points since 31 December 2024).
  • La Niña conditions of weak intensity in the equatorial Pacific (ONI OND 2025: −0.6 °C).

Source: NOAA NCEI

Mean temperature
12.1°C
+0.6 °C vs. normal (normal 11.5)
Slightly above normal
10th warmest of 47 (1979–2025) (tied with 1991, 2005, 2007)
Maximum temperature
17.9°C
+0.8 °C vs. normal (normal 17.1)
Slightly above normal
9th warmest of 47 (1979–2025) (tied with 2006, 2007)
Minimum temperature
6.3°C
+0.3 °C vs. normal (normal 5.9)
Normal
13th warmest of 47 (1979–2025) (tied with 1990, 2005, 2007)
Precipitation
836.7mm
81% of normal (normal 1034.5)
Near normal
5th driest of 47 (1979–2025)
Station records
2

Source: NOAA NCEI

2 Global and regional climate drivers

Sea-surface temperature anomaly, Year 2025 (°C, 1991–2020)

Sea-surface temperature anomaly, Year 2025 (°C, 1991–2020)

Source: NOAA NCEI / PSL

Sea-surface temperature anomaly in the Niño regions (°C)

RegionAnomaly (°C)Change from preceding period (°C)
Niño 1+20.20.3
Niño 3−0.2−0.5
Niño 3.4−0.3−0.7
Niño 4−0.2−0.8

Mean of the months in the period (OISST v2.1)

Source: NOAA CPC

La Niña conditions of weak intensity: the Oceanic Niño Index (ONI) for OND 2025 was −0.6 °C.

Source: NOAA CPC

Monthly Niño 3.4 anomaly, last 24 months (°C)

Monthly Niño 3.4 anomaly, last 24 months (°C)

Source: NOAA CPC

Teleconnection indices

IndexValuePhase
NAO0.0Neutral
AO0.2Neutral
PDO−2.0Negative

North Atlantic Oscillation (NAO); Arctic Oscillation (AO); Pacific Decadal Oscillation (PDO).

Source: NOAA CPC, NOAA NCEI

The Niño 3.4 anomaly was −0.31 °C (−0.71 °C relative to the preceding period).

Other indices: NAO +0.02 (neutral phase); AO +0.20 (neutral phase); PDO −1.99 (negative phase).

3 Precipitation

Statewide precipitation
836.7mm
81% of normal (normal 1034.5)
Near normal
5th driest of 47 (1979–2025)

Source: NOAA NCEI

Accumulated precipitation

Accumulated precipitation

Source: NOAA NCEI

Percent of normal precipitation (1991–2020)

Percent of normal precipitation (1991–2020)

Source: NOAA NCEI

Percent of normal by county

Percent of normal by county

Source: NOAA NCEI

Precipitation by region

RegionTotal (mm)Normal (mm)Difference (%)Category
Northwest804.7968.8−16.9Near normal
Northeast771.9960.4−19.6Near normal
West742.2986.8−24.8Below normal
Central712.5974.3−26.9Below normal
East717.9992.8−27.7Below normal
West Southwest784.21020.0−23.1Below normal
East Southeast953.31103.5−13.6Near normal
Southwest1022.91148.3−10.9Near normal
Southeast1075.31205.6−10.8Near normal

Source: NOAA NCEI

Stations with the largest precipitation excess

RegionCountyStationAltitude (m)Anomaly (%)
SoutheastPopeSmithland L&D109.018.9
SouthwestPulaskiOlmsted L&D114.015.7
East SoutheastMarionCentralia148.010.5
East SoutheastJasperNewton162.07.7
NorthwestRock IslandIllinois City Dam 16168.06.0
East SoutheastLawrenceLawrenceville 2WSW138.05.3
East SoutheastLawrenceLawrenceville Vincennes Intl A130.04.0
SoutheastFranklinW Frankfort131.03.4
East SoutheastClayFlora147.02.5
East SoutheastMarionSalem168.02.0

Source: NOAA NCEI

Stations with the largest precipitation deficit

RegionCountyStationAltitude (m)Anomaly (%)
EastFordPaxton243.0−59.6
EastChampaignChampaign Urbana Willard AP226.0−48.7
East SoutheastMoultrieSullivan 3S195.0−42.4
EastChampaignRantoul226.0−41.5
CentralTazewellMackinaw 3WSW202.0−41.3
EastChampaignChampaign 3S220.0−40.3
EastVermilionDanville Sewage Plt163.0−39.2
EastVermilionSidell 4N205.0−37.1
CentralDe WittClinton 1SSW212.0−36.6
EastChampaignFisher220.0−35.8

Source: NOAA NCEI

Largest 24-hour rainfall at stations

StationCountyMax 24 h rainfall (mm)Date
Shabbona 3SDeKalb152.42025-08-19
SalemMarion150.12025-04-05
Paw Paw 2SLee148.82025-08-19
CentraliaMarion124.72025-04-05
Lawrenceville 2WSWLawrence115.62025-04-05
WaltonvilleJefferson113.82025-04-05
NewtonJasper112.52025-04-04
1 ENE FairfieldWayne112.32025-04-05
Flora 2Clay111.52025-04-05
Kaskaskia Rvr Navigation LockRandolph111.52025-04-05

Source: NOAA NCEI

Statewide precipitation in each year

Statewide precipitation in each year

Source: NOAA NCEI

Monthly precipitation and 1991–2020 normal

Monthly precipitation and 1991–2020 normal

Source: NOAA NCEI

Statewide accumulated precipitation was 836.7 mm, 81% of the 1991–2020 average (1034.5 mm), category “Near normal”. It was the 5th driest year in the 1979–2025 series.

The region with the highest percentage of normal was Southeast (89%) and the lowest was East (72%).

Source: NOAA NCEI

4 Temperature

Mean temperature
12.1°C
+0.6 °C vs. normal (normal 11.5)
Slightly above normal
10th warmest of 47 (1979–2025) (tied with 1991, 2005, 2007)

Source: NOAA NCEI

Mean temperature

Mean temperature

Source: NOAA NCEI

Mean temperature anomaly (1991–2020)

Mean temperature anomaly (1991–2020)

Source: NOAA NCEI

Mean temperature anomaly by region

Mean temperature anomaly by region

Source: NOAA NCEI

Stations with the largest positive anomaly

RegionCountyStationAltitude (m)Anomaly (°C)
West SouthwestChristianMorrisonville192.02.1
SouthwestPerryDu Quoin 4 SE128.01.9
NorthwestWhitesideFulton L&D #13180.01.3
West SouthwestJerseyJerseyville 2 SW186.01.2
NorthwestMercerAledo224.01.2
WestWarrenMonmouth 4NW221.01.1
NorthwestJo DaviessElizabeth206.01.0
NorthwestBureauWalnut213.01.0
West SouthwestMorganJacksonville 2E186.01.0
WestHendersonGladstone L/D 18164.01.0

Source: NOAA NCEI

Stations with the largest negative anomaly

RegionCountyStationAltitude (m)Anomaly (°C)
East SoutheastLawrenceLawrenceville 2WSW138.0−0.5
NortheastLaSalleOttawa 4SW166.0−0.2
CentralMaconDecatur Wtp195.0−0.2
NorthwestJo DaviessStockton 3NNE296.0−0.1
East SoutheastShelbyWindsor210.0−0.0
East SoutheastDouglasTuscola198.0−0.0

Source: NOAA NCEI

Monthly statewide mean temperature anomaly

Monthly statewide mean temperature anomaly

Source: NOAA NCEI

Statewide mean temperature anomaly in each year

Statewide mean temperature anomaly in each year

Source: NOAA NCEI

The statewide mean temperature was 12.1 °C, 0.6 °C above the 1991–2020 average (11.5 °C), category “Slightly above normal”. It was the 10th warmest year in the 1979–2025 series (tied with 1991, 2005, 2007).

By region, the largest anomaly was in Northwest (+0.7 °C) and the smallest in Southeast (+0.4 °C).

Source: NOAA NCEI

Maximum temperature
17.9°C
+0.8 °C vs. normal (normal 17.1)
Slightly above normal
9th warmest of 47 (1979–2025) (tied with 2006, 2007)

Source: NOAA NCEI

Maximum temperature anomaly (1991–2020)

Maximum temperature anomaly (1991–2020)

Source: NOAA NCEI

Lowest and highest monthly mean maximum temperature by region

RegionLowest value (°C)StationHighest value (°C)Station
Northwest15.1Stockton 3NNE17.4Hennepin
Northeast14.4Chicago Northerly Is17.4Joliet
West16.7Galesburg18.7Quincy Dam 21
Central17.1Decatur Wtp18.6Decatur AP
East16.5Dwight Wwtp18.7Sidell 4N
West Southwest18.0Springfield Abraham Lincoln Ca19.7Hillsboro
East Southeast17.5Tuscola19.9Flora
Southwest19.2Carlyle Rsvr21.2Cairo 3N
Southeast18.7Harrisburg21.2Dixon Springs Agric Ctr

Station monthly means (GHCN-Daily, ≥ 80% of days with data).

Source: NOAA NCEI

The statewide maximum temperature was 17.9 °C, 0.8 °C above the 1991–2020 average (17.1 °C), category “Slightly above normal”. It was the 9th warmest year in the 1979–2025 series (tied with 2006, 2007).

By region, the largest anomaly was in West (+1.1 °C) and the smallest in Southeast (+0.3 °C).

Source: NOAA NCEI

Minimum temperature
6.3°C
+0.3 °C vs. normal (normal 5.9)
Normal
13th warmest of 47 (1979–2025) (tied with 1990, 2005, 2007)

Source: NOAA NCEI

Minimum temperature anomaly (1991–2020)

Minimum temperature anomaly (1991–2020)

Source: NOAA NCEI

Lowest and highest monthly mean minimum temperature by region

RegionLowest value (°C)StationHighest value (°C)Station
Northwest2.8Stockton 3NNE6.1Rock Is L&D 15
Northeast3.3Shabbona 5 NNE7.5Chicago Midway AP
West4.3Avon7.2Quincy Dam 21
Central4.6Congerville 2NW6.9Decatur AP
East4.4Dwight Wwtp6.9Sidell 4N
West Southwest6.0Jacksonville 2E8.0Alton - Melvin Price L&D
East Southeast5.2Casey8.3Newton
Southwest7.8Carbondale Sewage Plt11.0Cairo 3N
Southeast6.6Harrisburg9.2Dixon Springs Agric Ctr

Station monthly means (GHCN-Daily, ≥ 80% of days with data).

Source: NOAA NCEI

The statewide minimum temperature was 6.3 °C, 0.3 °C above the 1991–2020 average (5.9 °C), category “Normal”. It was the 13th warmest year in the 1979–2025 series (tied with 1990, 2005, 2007).

By region, the largest anomaly was in Southwest (+0.5 °C) and the smallest in East (+0.2 °C).

Source: NOAA NCEI

5 Climate extremes and records

Highest maximum temperature
37.8°C
Flora · 2025-09-15
Lowest minimum temperature
−28.8°C
Springfield Abraham Lincoln Ca · 2025-01-21
Highest 24 h rainfall
152.4mm
Shabbona 3S · 2025-08-19

Source: NOAA NCEI

Highest maximum temperature by county

CountyStationTemperature (°C)Date
ChampaignOgden37.82025-08-17
ChristianMorrisonville37.82025-09-15
ClayFlora37.82025-09-15
ColesCharleston37.22025-09-14
FranklinRend Lake Dam37.22025-08-16
JeffersonMt Vernon 3 NE37.22025-08-16
MaconDecatur AP37.22025-09-14
MadisonAlton - Melvin Price L&D37.22025-09-14
MarionSalem37.22025-09-15
MercerNew Boston Dam 1737.22025-09-15
Rock IslandRock Is L&D 1537.22025-08-15
St. ClairBelleville Siu Rsch37.02025-09-14
ClintonCarlyle Rsvr36.72025-09-15
HancockBentley36.72025-09-14
HendersonGladstone L/D 1836.72025-09-15
JacksonCarbondale Sthrn Illinois AP36.72025-08-19
JerseyJerseyville 2 SW36.72025-09-15
LawrenceLawrenceville Vincennes Intl A36.72025-06-23
MenardPetersburg 1E36.72025-06-27
MontgomeryHillsboro36.72025-09-15

The 20 most extreme of 69.

Source: NOAA NCEI

Lowest minimum temperature by county

CountyStationTemperature (°C)Date
SangamonSpringfield Abraham Lincoln Ca−28.82025-01-21
ChampaignChampaign 9 SW−26.72025-12-14
Jo DaviessElizabeth−26.72025-01-25
BureauWalnut−26.12025-01-21
McHenryMchenry Stratton Lock/Dam−26.12025-02-18
CarrollMt Carroll−25.62025-02-18
KaneChicago Aurora Muni AP−25.62025-12-04
LeePaw Paw 2S−25.62025-01-21
MaconDecatur AP−25.62025-12-14
WarrenMonmouth 4NW−25.62025-01-21
WhitesideMorrison−25.62025-01-21
DeKalbDe Kalb−25.02025-01-22
DouglasTuscola−25.02025-12-15
FultonAvon−25.02025-01-21
KnoxGalesburg−25.02025-01-22
LoganLincoln−25.02025-12-14
MercerAledo−25.02025-01-22
StephensonFreeport Wwtp−25.02025-01-21
WoodfordMinonk−25.02025-01-20
HancockLa Harpe−24.42025-01-21

The 20 most extreme of 69.

Source: NOAA NCEI

Station records broken

StationCountyVariableNew valueDatePrevious recordPrevious date
Lawrenceville 2WSWLawrenceHighest 24 h rainfall115.62025-04-05109.71995-05-18
Shabbona 3SDeKalbHighest 24 h rainfall152.42025-08-19143.52008-09-13

Most extreme daily value of the period against the same period in all earlier years of record (at least 20 years; for weeks, the same calendar month).

Source: NOAA NCEI

Climate-extremes indices (statewide mean)

IndexDescriptionValueNormalDifferenceUnit
TX90pWarm days (Tmax > 90th percentile)15.210.05.2%
TN90pWarm nights (Tmin > 90th percentile)12.510.02.5%
TX10pCool days (Tmax < 10th percentile)8.610.0−1.4%
TN10pCold nights (Tmin < 10th percentile)9.810.0−0.2%
FDFrost days (Tmin < 0 °C)105.4112.2−6.7d
SUSummer days (Tmax > 25 °C)135.8122.113.6d
TRTropical nights (Tmin > 20 °C)38.524.713.8d
WSDIWarm spell days (≥ 6 days)17.3——d
CSDICold spell days (≥ 6 days)10.5——d
Rx1dayMaximum 1-day precipitation57.659.9−2.3mm
Rx5dayMaximum 5-day precipitation100.2103.9−3.7mm
CDDConsecutive dry days (< 1 mm)19.319.00.2d
CWDConsecutive wet days (≥ 1 mm)5.76.3−0.6d

Percentile indices relative to calendar-day percentiles of 1991–2020 (5-day window); counts and maxima averaged over the state's grid cells.

Source: NOAA NCEI

Frost days by region

Frost days by region

Source: NOAA NCEI

Heat and cold waves

DatesTypeDetails
2025-01-20 – 2025-01-22Cold waveUp to 100% of the state below the 10th percentile of Tmin. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.
2025-02-18 – 2025-02-22Cold waveUp to 100% of the state below the 10th percentile of Tmin. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.
2025-03-11 – 2025-03-15Heat waveUp to 100% of the state above the 90th percentile of Tmax. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.
2025-06-22 – 2025-06-27Heat waveUp to 93% of the state above the 90th percentile of Tmax. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast and Southeast.
2025-08-16 – 2025-08-19Heat waveUp to 100% of the state above the 90th percentile of Tmax. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.
2025-08-25 – 2025-08-29Cold waveUp to 100% of the state below the 10th percentile of Tmin. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.
2025-09-04 – 2025-09-09Cold waveUp to 100% of the state below the 10th percentile of Tmin. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.
2025-09-14 – 2025-09-19Heat waveUp to 94% of the state above the 90th percentile of Tmax. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.
2025-09-28 – 2025-10-07Heat waveUp to 100% of the state above the 90th percentile of Tmax. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.
2025-12-24 – 2025-12-29Heat waveUp to 100% of the state above the 90th percentile of Tmax. Regions: Northwest, Northeast, West, Central, East, West Southwest, East Southeast, Southwest and Southeast.

Wave: at least 3 consecutive days with at least half of the state above the 90th percentile of maximum temperature (heat) or below the 10th percentile of minimum temperature (cold). At most the 10 most intense are listed.

Source: NOAA NCEI

6 Drought

U.S. Drought Monitor, 30 December 2025

U.S. Drought Monitor, 30 December 2025
Map valid from 30 December 2025. The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the USDA and NOAA. Map courtesy of NDMC.

Source: National Drought Mitigation Center, USDA, NOAA

Share of the state by drought category, weekly U.S. Drought Monitor maps (%)

Share of the state by drought category, weekly U.S. Drought Monitor maps (%)

Source: National Drought Mitigation Center, USDA, NOAA

Counties with the most severe drought, U.S. Drought Monitor of 30 December 2025 (% of the county)

CountyD0–D4 (%)D1–D4 (%)D2–D4 (%)D3–D4 (%)D4 (%)
Douglas100.0100.0100.0100.00.0
Champaign100.0100.0100.094.80.0
Piatt100.0100.0100.084.70.0
Ford100.0100.069.725.00.0
Vermilion100.0100.060.319.30.0
Coles100.0100.065.717.70.0
Moultrie100.0100.094.515.30.0
Edgar100.0100.088.110.50.0
Iroquois100.0100.024.22.50.0
McLean100.0100.072.91.40.0

Cumulative shares: D1–D4 is the share in moderate drought or worse.

Source: National Drought Mitigation Center, USDA, NOAA

Standardized Precipitation Index (SPI) ending December 2025

Standardized Precipitation Index (SPI) ending December 2025
SPI computed from NCLIMGRID; gamma distribution fitted to 1991–2020 accumulations.

Source: NOAA NCEI

Share of the state by SPI category

Share of the state by SPI category

Source: NOAA NCEI

Counties with the lowest SPI-12

CountySPI-6SPI-12Category
Champaign−2.1−3.0Extreme drought
Vermilion−2.0−2.8Extreme drought
Piatt−1.6−2.6Extreme drought
Douglas−1.7−2.5Extreme drought
De Witt−1.5−2.4Extreme drought
Ford−1.7−2.3Extreme drought
Edgar−1.7−2.3Extreme drought
Moultrie−1.4−2.2Extreme drought
McLean−1.4−2.0Severe drought
Sangamon−1.3−1.9Severe drought

Source: NOAA NCEI

U.S. Drought Monitor, map of 30 December 2025: 71% of the state in drought (D1–D4), 14% in severe drought or worse (D2–D4) and 4% in extreme or exceptional drought (D3–D4); 98% was abnormally dry or in drought (D0–D4).

On the map of 31 December 2024, 20% of the state was in drought: a change of +50 points over the period.

Counties with the largest share in severe drought or worse (D2–D4): Douglas (100%), Champaign (100%) and Piatt (100%).

SPI-12 (Jan–Dec 2025): statewide mean −1.28; 69% of the state in drought (SPI ≤ −1.0) and 36% in severe or extreme drought.

Most affected counties: Champaign (−3.00), Vermilion (−2.84) and Piatt (−2.65).

SPI-6 (Jul–Dec 2025): 49% of the state in drought.

7 Severe weather and notable events

Notable events

DatesTypeAreaDetails
2025-04-05Heavy rainSalem150.1 mm in 24 hours.
2025-08-19Heavy rainShabbona 3S152.4 mm in 24 hours.

GDACS alerts and station rainfall of 150 mm or more in 24 hours (after quality control).

Source: GDACS, NOAA NCEI

9 Outlook

Outlook for Jan–Mar 2026: most likely tercile

Outlook for Jan–Mar 2026: most likely tercile

Source: NOAA CPC

Probability of each tercile by region, Jan–Mar 2026 (%)

RegionPrecipitation: belowPrecipitation: normalPrecipitation: aboveTemp.: belowTemp.: normalTemp.: above
Northwest32.032.035.023.028.049.0
Northeast32.032.036.022.027.050.0
West32.035.034.022.023.054.0
Central31.034.035.023.022.056.0
East29.035.036.022.025.053.0
West Southwest31.034.035.023.024.053.0
East Southeast27.037.036.021.027.052.0
Southwest28.036.036.021.027.052.0
Southeast27.038.035.020.029.051.0

Source: NOAA CPC

Probabilistic outlook from the North American Multi-Model Ensemble (NMME), initialised in January 2026, relative to 1991–2020 terciles. It is not an official forecast: consult the National Weather Service and NOAA's Climate Prediction Center.

Precipitation, Jan–Mar 2026: above normal is favoured over 2% of the state and below normal over 0%.

Mean temperature, Jan–Mar 2026: above normal is favoured over 100% of the state and below normal over 0%.

10 Annexes

Report climate regions

Report climate regions

Monthly precipitation by region (mm)

RegionJanFebMarAprMayJunJulAugSepOctNovDec
Northwest16.218.470.467.874.0100.5213.888.217.647.449.241.2
Northeast18.220.085.570.655.789.7142.598.133.353.353.451.5
West15.58.567.873.390.5106.7200.525.927.038.842.245.3
Central21.210.671.184.076.7103.8160.038.220.241.043.142.6
East19.012.185.488.975.5101.4127.250.430.342.143.342.4
West Southwest28.514.671.4141.291.590.5171.117.930.855.450.221.0
East Southeast33.132.978.4206.595.8104.6161.125.242.380.758.034.8
Southwest53.565.160.1239.4109.4125.5111.222.049.9110.853.922.2
Southeast52.080.065.5241.9122.7134.5103.025.369.3102.051.128.0

CSV

Source: NOAA NCEI

Monthly maximum temperature by region (°C)

RegionJanFebMarAprMayJunJulAugSepOctNovDec
Northwest−1.30.413.116.622.128.629.627.426.820.59.90.6
Northeast−1.41.112.716.020.728.529.927.826.119.79.71.0
West−0.42.615.618.522.828.730.528.728.022.011.83.0
Central−0.73.415.318.423.229.030.828.728.421.811.62.9
East−1.23.114.517.722.329.230.728.427.821.311.02.5
West Southwest0.34.317.019.323.129.131.529.528.822.713.15.3
East Southeast0.34.716.319.222.829.331.729.328.822.412.75.1
Southwest2.35.918.020.523.129.432.130.429.022.914.27.7
Southeast2.36.217.720.223.029.332.130.328.922.413.97.3

CSV

Source: NOAA NCEI

Monthly mean temperature by region (°C)

RegionJanFebMarAprMayJunJulAugSepOctNovDec
Northwest−6.7−4.36.610.315.522.624.321.719.514.24.8−4.4
Northeast−6.2−3.46.510.014.622.424.622.119.514.05.0−3.8
West−5.5−2.38.412.116.523.125.322.720.615.76.2−2.1
Central−5.6−1.68.312.016.723.325.522.620.415.26.0−2.2
East−6.1−1.87.811.316.123.225.322.320.114.55.5−2.6
West Southwest−4.5−0.89.712.917.223.826.323.521.216.27.5−0.1
East Southeast−4.4−0.19.412.917.224.026.623.221.215.77.40.2
Southwest−2.51.011.014.618.024.627.224.222.016.58.72.5
Southeast−2.51.210.814.317.924.527.124.121.816.18.62.6

CSV

Source: NOAA NCEI

Monthly minimum temperature by region (°C)

RegionJanFebMarAprMayJunJulAugSepOctNovDec
Northwest−12.0−9.10.23.98.916.519.015.912.27.9−0.4−9.4
Northeast−10.9−7.90.34.08.416.319.316.512.88.20.2−8.5
West−10.5−7.31.25.710.217.420.216.713.29.40.7−7.2
Central−10.5−6.71.35.610.217.620.216.512.48.60.4−7.4
East−10.9−6.81.14.99.917.219.916.212.47.80.0−7.6
West Southwest−9.4−5.92.46.511.318.421.117.513.69.71.8−5.5
East Southeast−9.1−4.92.66.711.618.721.517.213.69.02.0−4.6
Southwest−7.4−4.03.98.713.019.822.317.914.910.23.2−2.8
Southeast−7.4−3.73.98.412.919.622.217.914.79.73.3−2.0

CSV

Source: NOAA NCEI

Stations used

IdNameCountyLatitudeLongitudeAltitude (m)Days with data (Tmax) (%)
USC00110072AledoMercer41.2−90.7223.799.0
USC00110082Alexis 1 SWWarren41.1−90.6204.80.0
USC00110137Alton - Melvin Price L&DMadison38.9−90.1123.483.0
USC00110140AltonaKnox41.1−90.2233.20.0
USC00110146Amboy WaterLee41.7−89.3230.10.0
USC00110187Anna 4 NUnion37.5−89.2180.799.0
USC00110251Arthur 1WMoultrie39.7−88.5204.20.0
USC00110306Athens 4SWMenard39.9−89.8181.10.0
USC00110330AugustaHancock40.2−90.9203.60.0
USC00110338Aurora WaterKane41.8−88.3205.7100.0
USC00110356AvonFulton40.7−90.4195.199.0
USC00110442Barrington 3SWCook42.1−88.2269.199.0
USC00110500Beecher CityEffingham39.2−88.8185.30.0
USC00110583Belvidere WwtpBoone42.3−88.9229.50.0
USC00110598BentleyHancock40.3−91.1198.199.0
USC00110761Bloomington Wtr WksMcLean40.5−89.0233.50.0
USC00110803Bourbonnais 3NWKankakee41.2−87.9200.60.0
USC00111083Buffalo 3NNESangamon39.9−89.4187.10.0
USC00111250CantonFulton40.5−90.0195.10.0
USC00111265Carbondale Sewage PltJackson37.7−89.2118.993.0
USC00111290Carlyle RsvrClinton38.6−89.4152.7100.0
USC00111329CaseyClark39.3−88.0189.0100.0
USC00111386CentraliaMarion38.6−89.1147.80.0
USC00111436CharlestonColes39.5−88.2213.498.0
USC00111447ChatsworthLivingston40.8−88.3220.10.0
USC00111491ChesterRandolph37.9−89.8118.90.0
USC00111550Chicago Northerly IsCook41.9−87.6177.798.0
USC00111577Chicago Midway AP 3SWCook41.7−87.8189.0100.0
USC00111655CiscoPiatt40.0−88.7209.70.0
USC00111664Cisne 2 SWayne38.5−88.4138.40.0
USC00111700Clay City 6SSEClay38.6−88.3140.20.0
USC00111743Clinton 1SSWDe Witt40.1−89.0211.80.0
USC00111836Congerville 2NWWoodford40.6−89.2195.1100.0
USC00112048Crystal Lake 4NWMcHenry42.3−88.4283.874.0
USC00112140DanvilleVermilion40.1−87.6169.299.0
USC00112145Danville Sewage PltVermilion40.1−87.6163.40.0
USC00112193Decatur WtpMacon39.8−89.0194.898.0
USC00112223De KalbDeKalb41.9−88.8267.6100.0
USC00112348Dixon WwtpLee41.8−89.5198.1100.0
USC00112353Dixon Springs Agric CtrPope37.4−88.7160.696.0
USC00112483Du Quoin 4 SEPerry38.0−89.2128.095.0
USC00112500Dwight WwtpLivingston41.1−88.4190.599.0
USC00112510Earlville 3SLaSalle41.6−88.9210.90.0
USC00112679Edwardsville 2 WMadison38.8−90.0141.70.0
USC00112685Effingham SEEffingham39.1−88.5161.80.0
USC00112736Elgin WaterKane42.1−88.3227.199.0
USC00112745ElizabethJo Daviess42.3−90.2205.798.0
USC00112923Fairbury WwtpLivingston40.8−88.5204.20.0
USC001129311 ENE FairfieldWayne38.4−88.4140.8100.0
USC00113061FisherChampaign40.3−88.3219.80.0
USC00113106FloraClay38.7−88.5146.6100.0
USC00113107Flora 2Clay38.7−88.5149.00.0
USC00113120Ft Massac SpMassac37.1−88.7104.20.0
USC00113132ForrestonOgle42.1−89.6278.30.0
USC00113262Freeport WwtpStephenson42.3−89.6228.6100.0
USC00113290Fulton L&D #13Whiteside41.9−90.2180.499.0
USC00113320GalesburgKnox40.9−90.4232.099.0
USC00113335GalvaHenry41.2−90.0246.9100.0
USC00113384GeneseoHenry41.5−90.1194.8100.0
USC00113392Genoa 2SWDeKalb42.1−88.7251.80.0
USC00113395Germantown HillsWoodford40.8−89.5238.70.0
USC00113455Gladstone L/D 18Henderson40.9−91.0164.091.0
USC00113490Glen Ellyn 4SDuPage41.8−88.1207.30.0
USC00113580Olmsted L&DPulaski37.2−89.1114.391.0
USC00113879HarrisburgSaline37.7−88.5111.391.0
USC00113902Harvard WwtpMcHenry42.4−88.6279.20.0
USC00113940HavanaMason40.3−90.1141.10.0
USC00114012HennepinPutnam41.3−89.3157.0100.0
USC00114089HighlandMadison38.7−89.7158.50.0
USC00114108HillsboroMontgomery39.2−89.5192.099.0
USC00114198HoopestonVermilion40.5−87.7216.499.0
USC00114317HutsonvilleCrawford39.1−87.7147.20.0
USC00114355Illinois City Dam 16Rock Island41.4−91.0167.699.0
USC00114400Iuka 12 SWMarion38.5−89.0179.843.0
USC00114442Jacksonville 2EMorgan39.7−90.2185.9100.0
USC00114447Jacksonville 2Morgan39.7−90.2190.8100.0
USC00114489Jerseyville 2 SWJersey39.1−90.3185.995.0
USC00114530Joliet Brandon Road Lock/DamWill41.5−88.1165.5100.0
USC00114603Kankakee WwtpKankakee41.1−87.9182.999.0
USC00114629Kaskaskia Rvr Navigation LockRandolph38.0−89.9118.998.0
USC00114710Kewanee 1EHenry41.2−89.9237.798.0
USC00114780KnoxvilleKnox40.9−90.3221.9100.0
USC00114805LaconMarshall41.0−89.4139.60.0
USC00114823La HarpeHancock40.6−91.0206.797.0
USC00114833Lake SpringfieldSangamon39.8−89.6177.10.0
USC00114890Lansing 2SCook41.5−87.5187.10.0
USC00114957Lawrenceville 2WSWLawrence38.7−87.7137.5100.0
USC00115079LincolnLogan40.2−89.3177.7100.0
USC00115097Lisle - Morton ArboretumDuPage41.8−88.1206.398.0
USC00115110Little Red School HouseCook41.7−87.9219.20.0
USC00115219LovingtonMoultrie39.7−88.6207.90.0
USC00115272Mackinaw 3WSWTazewell40.5−89.4201.80.0
USC00115280MacombMcDonough40.5−90.7185.90.0
USC00115314Manhattan 5ENEWill41.5−87.9228.00.0
USC00115342Marion 4 NNEWilliamson37.8−88.9145.40.0
USC00115372Marseilles Lock/DamLaSalle41.3−88.8148.499.0
USC00115430MattoonColes39.5−88.4213.40.0
USC00115493Mchenry Stratton Lock/DamMcHenry42.3−88.3224.3100.0
USC00115539Medora 1 SMacoupin39.2−90.1185.00.0
USC00115562Mendota 1SLaSalle41.5−89.1218.80.0
USC00115660Milstadt 2SWSt. Clair38.4−90.1198.10.0
USC00115712MinonkWoodford40.9−89.0228.6100.0
USC00115763MoneeWill41.4−87.8242.90.0
USC00115768MonmouthWarren40.9−90.6219.594.0
USC00115772Monmouth 4NWWarren40.9−90.7220.799.0
USC00115825Morris 1NWGrundy41.4−88.4159.7100.0
USC00115833MorrisonWhiteside41.8−90.0192.6100.0
USC00115841MorrisonvilleChristian39.4−89.5192.099.0
USC00115876MortonTazewell40.6−89.5213.70.0
USC00115901Mt CarrollCarroll42.1−90.0215.898.0
USC00115917Mt Olive 1 EMacoupin39.1−89.7204.20.0
USC00115927Mt PulaskiLogan40.0−89.3201.50.0
USC00115943Mt Vernon 3 NEJefferson38.4−88.9149.479.0
USC00115950Moweaqua 2SShelby39.6−89.0190.50.0
USC00115983Murphysboro 2 SWJackson37.8−89.4167.60.0
USC00116024NeogaCumberland39.3−88.5195.70.0
USC00116080New Boston Dam 17Mercer41.2−91.1166.792.0
USC00116157NewtonJasper39.0−88.2161.8100.0
USC00116200Normal 4NEMcLean40.5−88.9240.899.0
USC00116344OgdenChampaign40.1−88.0205.798.0
USC00116446Olney 2SRichland38.7−88.1139.9100.0
USC00116490OregonOgle42.0−89.3206.70.0
USC00116526Ottawa 4SWLaSalle41.3−88.9166.1100.0
USC00116579PanaChristian39.4−89.1198.1100.0
USC00116610Paris StpEdgar39.6−87.7197.892.0
USC00116616Park Forest WaterCook41.5−87.7216.4100.0
USC00116661Paw Paw 2SLee41.7−89.0271.099.0
USC00116663PaxtonFord40.5−88.1242.90.0
USC00116710Peoria 5NWPeoria40.7−89.6213.40.0
USC00116725PeotoneWill41.3−87.8218.80.0
USC00116738Perry 6 NWPike39.8−90.8198.121.0
USC00116753PeruLaSalle41.3−89.1193.2100.0
USC00116765Petersburg 1EMenard40.0−89.8182.9100.0
USC00116769PhiloChampaign40.0−88.2219.50.0
USC00116779Pinckneyville 2 NPerry38.1−89.4131.10.0
USC00116837Pittsfield #2Pike39.6−90.8207.367.0
USC00116874PlumfieldFranklin37.9−89.0119.80.0
USC00116970Prairie City 2SMcDonough40.6−90.5198.110.0
USC00117077Quincy Dam 21Adams39.9−91.4147.292.0
USC00117157Red Bud 2 SRandolph38.2−90.0128.00.0
USC00117187Rend Lake DamFranklin38.0−89.0138.787.0
USC00117329RoanokeWoodford40.8−89.2219.50.0
USC00117345RobinsonCrawford39.0−87.8163.1100.0
USC00117391Rock Is L&D 15Rock Island41.5−90.6173.190.0
USC00117457Romeoville WfoWill41.6−88.1201.2100.0
USC00117487ElizabethtownHardin37.4−88.3110.30.0
USC00117636SalemMarion38.6−88.9167.699.0
USC00117833Shabbona 3SDeKalb41.7−88.9259.10.0
USC00117860Shawneetown 3 WSWGallatin37.7−88.2121.90.0
USC00117876Shelbyville DamShelby39.4−88.8198.199.0
USC00117896ShermanSangamon39.9−89.6177.10.0
USC00117952Sidell 4NVermilion40.0−87.8204.8100.0
USC00118020Smithland L&DPope37.2−88.4108.897.0
USC00118194St AnneKankakee41.0−87.7203.00.0
USC00118210St LiborySt. Clair38.4−89.7129.50.0
USC00118248SteelevilleRandolph38.0−89.7131.10.0
USC00118254Steward 3SLee41.8−89.0246.90.0
USC00118293Stockton 3NNEJo Daviess42.4−90.0295.7100.0
USC00118353Streator 2SELivingston41.1−88.8184.70.0
USC00118389Sullivan 3SMoultrie39.6−88.6195.10.0
USC00118491Taylorville 2SEChristian39.5−89.3188.10.0
USC00118684TuscolaDouglas39.8−88.3198.4100.0
USC00118740Champaign 3SChampaign40.1−88.2220.1100.0
USC00118781VandaliaFayette39.0−89.1149.40.0
USC00118916WalnutBureau41.6−89.6213.498.0
USC00118932WaltonvilleJefferson38.2−89.1155.80.0
USC00119002Waterloo 6SWMonroe38.3−90.2222.50.0
USC00119021Watseka Public WorksIroquois40.8−87.7191.10.0
USC00119148W FrankfortFranklin37.9−88.9131.10.0
USC00119241White Hall 1 EGreene39.4−90.4176.899.0
USC00119275WillisvilleRandolph38.0−89.6151.20.0
USC00119354WindsorShelby39.4−88.6210.399.0
USC00119480Woodstock 5NWMcHenry42.4−88.5288.60.0
USC00119816Yates CityKnox40.8−90.0203.90.0
USW00003887Decatur APMacon39.8−88.9205.1100.0
USW00003960Cahokia St Louis Dwtn APSt. Clair38.6−90.1123.499.0
USW00004808Chicago Aurora Muni APKane41.8−88.5213.7100.0
USW00004838Chicago Palwaukee APCook42.1−87.9191.7100.0
USW00013802Belleville Siu RschSt. Clair38.5−89.8137.298.0
USW00013809Lawrenceville Vincennes Intl ALawrence38.8−87.6130.1100.0
USW00014806RantoulChampaign40.3−88.2225.60.0
USW00014819Chicago Midway APCook41.8−87.8185.9100.0
USW00014834JolietWill41.5−88.1167.998.0
USW00014842General Wayne A Downing Intl APeoria40.7−89.7199.6100.0
USW00014880Chicago Waukegan Rgnl APLake42.4−87.9216.4100.0
USW00014923Moline Quad City Intl APRock Island41.4−90.5175.6100.0
USW00053802Mattoon Charleston Coles Co APColes39.5−88.3216.499.0
USW00054808Champaign 9 SWChampaign40.1−88.4213.4100.0
USW00054811Shabbona 5 NNEDeKalb41.8−88.9262.4100.0
USW00054831Bloomington Normal APMcLean40.5−89.0263.799.0
USW00093809Cairo 3NAlexander37.0−89.295.497.0
USW00093810Carbondale Sthrn Illinois APJackson37.8−89.2121.999.0
USW00093822Springfield Abraham Lincoln CaSangamon39.8−89.7179.8100.0
USW00093989Quincy Rgnl APAdams39.9−91.2231.6100.0
USW00094822Rockford Gtr Rockford APWinnebago42.2−89.1221.0100.0
USW00094846Chicago Ohare Intl APDuPage42.0−87.9204.8100.0
USW00094870Champaign Urbana Willard APChampaign40.0−88.3226.599.0
USW00094892Chicago W Chicago Dupage APDuPage41.9−88.3228.3100.0

CSV

Source: NOAA NCEI

11 Glossary, methodology and sources

Anomaly: difference between the observed value and its 1991–2020 normal. Percent of normal: observed total divided by the normal, times 100. Station record: most extreme daily value for the same month in all earlier years of record (at least 20 years).

Temperature: NOAA nClimGrid-Daily. Precipitation: NOAA nClimGrid-Daily. nClimGrid-Daily is the grid behind NOAA's official statewide values; it is averaged here from 1/24° to 1/8° (about 12 km). Mean temperature is (Tmax + Tmin)/2. Statewide, regional and county averages are weighted by the area of each grid cell inside each polygon. Temperature maps, frost days and annex tables are given by region; regions are NOAA NCEI climate divisions, with each county in the division of its centroid. Recent weeks use NCEI's preliminary file of the month; such reports are marked preliminary and updated when the final file is published. Normals refer to 1991-2020; ranks compare values rounded to one decimal. Stations: GHCN-Daily (NOAA NCEI) cooperative and first-order stations; values flagged by its quality control are discarded, as are daily values more than 5 robust standard deviations from the station median and variables whose monthly anomaly differs by more than 3 °C from the gridded analysis. Period means require at least 80% of days with data and station normals at least 20 complete years. This report is generated automatically and does not replace official information from the National Weather Service or the state climatologist.

SourceProductLicenseCitation
NOAA CPCONI, Niño-region SST indices (OISST v2.1), NAO and AOPublic domain (NOAA)NOAA Climate Prediction Center climate indices.
NOAA NCEI / PSLExtended Reconstructed SST v5 (ERSST v5), 2°Public domain (NOAA)Huang et al. (2017), J. Climate, doi:10.1175/JCLI-D-16-0836.1
GDACSGlobal Disaster Alert and Coordination System event listSee provider terms—
NOAA NCEIGHCN-DailyPublic domain (NOAA)Menne et al. (2012), J. Atmos. Oceanic Technol., doi:10.1175/JTECH-D-11-00103.1
NOAA NCEIPacific Decadal Oscillation index (ERSST v5)Public domain (NOAA)—
NOAA NCEInClimGrid-Daily, contiguous United States (1/24°, averaged here to 1/8°)Public domain (NOAA)Durre, I., et al. (2022). NOAA's nClimGrid-Daily Version 1. NOAA National Centers for Environmental Information. doi:10.25921/c4gt-r169
NOAA CPCNorth American Multi-Model Ensemble (NMME) tercile probabilities, 1°Public domain (NOAA)Kirtman et al. (2014), Bull. Amer. Meteor. Soc., doi:10.1175/BAMS-D-12-00050.1
National Drought Mitigation Center, USDA, NOAAU.S. Drought Monitor, weekly maps and area statisticsFree to use with credit (NDMC)The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture and the National Oceanic and Atmospheric Administration. Map courtesy of NDMC.
US Census Bureau TIGERwebUS Census Bureau, TIGERweb counties (generalised)Public domain (US Government work)—

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