Illinois climate: Statewide normals, its places and each month, NOAA 1991-2020
Illinois's statewide normal is 52.6°F a year with 40.7 inches of precipitation (NOAA nClimDiv, 1991-2020); it has warmed 1.4°F per century since 1895, and 2012 was its warmest year.
- Statewide normal temperature
- 52.6°Fyear, 1991-2020
- Statewide normal precipitation
- 40.7 inyear, 1991-2020
- Last five years against normal
- +1.3°F2021-2025 mean 53.9°F
- Places with normals
- 170144 Census places, 26 other stations
What is Illinois's weather like each month?
Statewide, July is the warmest month and January the coldest. Each month has its own page with the warmest and coolest places that month:
- Jan35°19°
- Feb40°22°
- Mar51°32°
- Apr64°41°
- May74°52°
- Jun83°62°
- Jul86°65°
- Aug84°63°
- Sep78°55°
- Oct66°44°
- Nov51°33°
- Dec39°24°
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 35°F | 19°F | 26.7°F | 2.31 |
| February | 40°F | 22°F | 31.1°F | 2.11 |
| March | 51°F | 32°F | 41.4°F | 2.94 |
| April | 64°F | 41°F | 52.6°F | 4.24 |
| May | 74°F | 52°F | 63.3°F | 4.77 |
| June | 83°F | 62°F | 72.2°F | 4.65 |
| July | 86°F | 65°F | 75.4°F | 4.06 |
| August | 84°F | 63°F | 73.6°F | 3.56 |
| September | 78°F | 55°F | 66.8°F | 3.35 |
| October | 66°F | 44°F | 54.9°F | 3.26 |
| November | 51°F | 33°F | 42.1°F | 3.08 |
| December | 39°F | 24°F | 31.6°F | 2.43 |
Source: NOAA NCEI nClimDiv statewide series (Climate at a Glance); data files. Statewide values are area-weighted from a 5 km grid of station data, so they differ from the simple average of a state's stations.
Has Illinois been warmer than normal?
4 of the 5 complete years since 2021 ran warmer than the 1991-2020 statewide normal of 52.6°F. The record since 1895 rises at a fitted 1.4°F per century; the warmest year was 2012 (55.8°F).
| Year | Mean | Against normal |
|---|---|---|
| 2021 | 53.8°F | +1.1°F |
| 2022 | 52.1°F | −0.6°F |
| 2023 | 54.7°F | +2.1°F |
| 2024 | 55.5°F | +2.9°F |
| 2025 | 53.6°F | +1.0°F |
Source: NOAA NCEI nClimDiv statewide annual series.
Where is it warmest, wettest and snowiest in Illinois?
Among the places PlainClimate covers, Anna has the warmest year (58.5°F) and Galena the coolest (47.0°F); Anna is the wettest (51.1 in) and Wheeling the driest (32.3 in), and Lake Villa gets the most snow (43 in).
| Place | Year | July high | January low | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|
| Chicago | 51.2°F | 85°F | 19°F | 37.9 | 38 | April 16 |
| Aurora | 50.2°F | 84°F | 16°F | 39.5 | 28 | April 19 |
| Joliet | 50.4°F | 84°F | 17°F | 38.0 | 17 | April 19 |
| Rockford | 49.4°F | 84°F | 15°F | 37.2 | 37 | April 24 |
| Elgin | 49.0°F | 84°F | 14°F | 39.9 | 32 | April 26 |
| Springfield | 54.0°F | 87°F | 20°F | 38.0 | 22 | April 14 |
| Peoria | 52.7°F | 86°F | 18°F | 37.5 | 26 | April 16 |
| Champaign | 52.5°F | 85°F | 18°F | 37.0 | – | April 19 |
| Waukegan | 48.4°F | 82°F | 16°F | – | – | April 30 |
| Bloomington | 50.2°F | 84°F | 16°F | 40.4 | – | April 21 |
| Decatur | 53.1°F | 86°F | 20°F | 36.4 | – | April 16 |
| Wheaton | 51.1°F | 86°F | 17°F | 39.9 | 24 | April 27 |
| Normal | 51.1°F | 86°F | 16°F | 39.4 | 20 | April 25 |
| Moline | 51.2°F | 86°F | 15°F | 38.3 | 36 | April 24 |
| Crystal Lake | 49.1°F | 84°F | 14°F | 39.4 | 35 | April 25 |
| Romeoville | 50.9°F | 85°F | 16°F | 41.1 | 33 | April 20 |
| Belleville | 57.7°F | 90°F | 24°F | 43.4 | 11 | April 12 |
| DeKalb | 48.6°F | 83°F | 13°F | 37.3 | 33 | April 24 |
| Quincy | 53.0°F | 86°F | 19°F | 36.4 | – | April 14 |
| Streamwood | 49.6°F | 87°F | 14°F | 38.0 | 34 | April 30 |
| Wheeling | 50.8°F | 84°F | 18°F | 32.3 | – | April 19 |
| Rock Island | 50.3°F | 84°F | 13°F | 38.8 | – | April 19 |
| Mundelein | 47.9°F | 82°F | 14°F | 38.5 | 43 | April 29 |
| Galesburg | 50.2°F | 84°F | 14°F | 39.0 | 26 | April 20 |
| Burbank | 52.4°F | 85°F | 20°F | 40.9 | 39 | April 10 |
| Danville | 53.1°F | 85°F | 20°F | 43.2 | – | April 21 |
| West Chicago | 49.7°F | 84°F | 16°F | 33.2 | – | April 25 |
| Alton | 55.7°F | 87°F | 22°F | 41.9 | – | April 4 |
| Lisle | 49.2°F | 84°F | 15°F | 40.2 | – | April 28 |
| Kankakee | 51.2°F | 85°F | 16°F | 41.7 | 21 | April 19 |
| Freeport | 47.7°F | 82°F | 11°F | 38.4 | 35 | April 26 |
| Carbondale | 56.4°F | 88°F | 25°F | 44.0 | – | April 9 |
| Park Forest | 49.8°F | 84°F | 15°F | 42.1 | 28 | April 23 |
| Ottawa | 50.2°F | 83°F | 15°F | 36.2 | 24 | April 20 |
| Jacksonville | 52.8°F | 87°F | 18°F | 41.4 | – | April 17 |
| Charleston | 55.0°F | 88°F | 21°F | 43.8 | 19 | April 15 |
| Cahokia Heights | 56.5°F | 89°F | 24°F | 40.8 | – | April 8 |
| Mattoon | 53.4°F | 86°F | 20°F | 36.0 | – | April 15 |
| Dixon | 49.4°F | 83°F | 14°F | 40.5 | 31 | April 21 |
| Antioch | 48.6°F | 82°F | 15°F | – | – | April 23 |
| Morris | 50.8°F | 85°F | 16°F | 38.8 | 25 | April 20 |
| Channahon | 51.1°F | 85°F | 17°F | 37.2 | 18 | April 16 |
| Mount Vernon | 54.5°F | 86°F | 22°F | 45.0 | 10 | April 11 |
| Lincoln | 52.2°F | 86°F | 18°F | 39.8 | 19 | April 20 |
| Effingham | 54.4°F | 89°F | 20°F | 44.0 | 15 | April 13 |
| Streator | 51.6°F | 88°F | 16°F | 39.4 | 26 | April 12 |
| Rantoul | 52.3°F | 88°F | 16°F | 40.4 | – | April 21 |
| Kewanee | 49.6°F | 84°F | 14°F | 39.6 | 31 | April 24 |
| Pontiac | 51.8°F | 84°F | 17°F | 37.0 | 25 | April 16 |
| Barrington | 48.0°F | 81°F | 13°F | 40.4 | 39 | April 25 |
| Peru | 49.6°F | 84°F | 14°F | 38.0 | 29 | April 24 |
| Rochelle | 47.9°F | 82°F | 12°F | 36.6 | – | April 26 |
| Lake Villa | 48.6°F | 82°F | 15°F | 37.8 | 43 | April 24 |
| Monmouth | 50.6°F | 84°F | 15°F | 39.4 | 26 | April 22 |
| Olney | 54.2°F | 87°F | 21°F | 48.8 | 11 | April 15 |
| Jerseyville | 53.4°F | 87°F | 19°F | 42.2 | 13 | April 14 |
| Paris | 51.4°F | 84°F | 17°F | 42.7 | 19 | April 21 |
| Harrisburg | 57.3°F | 89°F | 24°F | 47.6 | – | April 7 |
| Marengo | 48.2°F | 84°F | 13°F | 37.6 | 31 | April 28 |
| Princeton | 49.7°F | 85°F | 14°F | 39.8 | 29 | April 22 |
| Vandalia | 54.2°F | 87°F | 21°F | 43.7 | – | April 10 |
| Robinson | 54.1°F | 87°F | 20°F | 45.5 | – | April 13 |
| Salem | 54.9°F | 88°F | 21°F | 45.9 | 10 | April 9 |
| Mount Carmel | 56.4°F | 87°F | 25°F | 48.7 | 9 | April 2 |
| Benton | 56.3°F | 88°F | 25°F | – | – | April 4 |
| Geneseo | 50.9°F | 86°F | 15°F | 39.1 | 28 | April 20 |
| Hillsboro | 55.5°F | 89°F | 21°F | 42.1 | – | April 13 |
| Du Quoin | 56.0°F | 87°F | 24°F | 47.7 | 12 | April 6 |
| Carlinville | 53.4°F | 86°F | 19°F | 40.0 | 17 | April 14 |
| Pana | 53.6°F | 87°F | 19°F | 42.3 | 15 | April 17 |
| Fairfield | 57.1°F | 90°F | 25°F | 46.0 | – | April 7 |
| Marseilles | 49.7°F | 84°F | 14°F | 39.0 | 25 | April 27 |
| Hoopeston | 52.2°F | 85°F | 18°F | 40.9 | 20 | April 22 |
| Carmi | 55.0°F | 88°F | 21°F | 48.3 | 12 | April 15 |
| Tuscola | 52.4°F | 85°F | 18°F | 40.5 | 17 | April 15 |
| Flora | 55.0°F | 89°F | 21°F | 48.0 | 12 | April 9 |
| Shelbyville | 53.6°F | 86°F | 19°F | 41.4 | – | April 10 |
| Watseka | 50.8°F | 85°F | 16°F | 38.4 | 17 | April 24 |
| Paxton | 50.5°F | 84°F | 15°F | 37.9 | 18 | April 23 |
| Lawrenceville | 55.7°F | 88°F | 23°F | 41.7 | – | April 8 |
| Sullivan | 53.0°F | 86°F | 19°F | 41.6 | 13 | April 15 |
| Anna | 58.5°F | 90°F | 25°F | 51.1 | 10 | April 8 |
| Pittsfield | 53.8°F | 88°F | 19°F | 40.5 | 16 | April 14 |
| Sparta | 55.1°F | 88°F | 22°F | 45.6 | 11 | April 12 |
| Dwight | 49.3°F | 84°F | 14°F | 37.7 | 23 | April 27 |
| Morrison | 48.3°F | 83°F | 12°F | 38.3 | 32 | April 26 |
| Fulton | 49.9°F | 84°F | 14°F | 34.3 | – | April 13 |
| Aledo | 50.0°F | 85°F | 13°F | 39.1 | 22 | April 22 |
| Gibson City | 50.7°F | 84°F | 16°F | 37.7 | 18 | April 21 |
| Carlyle | 55.7°F | 88°F | 22°F | 45.9 | – | April 6 |
| Galena | 47.0°F | 82°F | 10°F | 39.6 | 38 | April 26 |
| Virden | 54.8°F | 87°F | 21°F | 38.4 | 16 | April 7 |
| Nashville | 55.1°F | 87°F | 21°F | 42.2 | 12 | April 7 |
| Rushville | 51.7°F | 85°F | 17°F | 40.9 | – | April 16 |
| Knoxville | 50.4°F | 84°F | 14°F | 40.5 | 25 | April 21 |
| Havana | 52.5°F | 88°F | 16°F | 41.0 | 28 | April 17 |
| Newton | 54.5°F | 86°F | 22°F | 46.0 | 16 | April 13 |
| McLeansboro | 55.4°F | 89°F | 22°F | 47.1 | 13 | April 11 |
| Galva | 49.5°F | 84°F | 13°F | 38.7 | – | April 26 |
| Casey | 54.1°F | 88°F | 19°F | 45.5 | 12 | April 14 |
| Polo | 49.3°F | 85°F | 13°F | 40.0 | – | April 29 |
| White Hall | 52.9°F | 86°F | 18°F | 39.6 | 18 | April 13 |
| Petersburg | 52.3°F | 86°F | 17°F | 37.6 | 15 | April 13 |
| Mason City | 51.7°F | 85°F | 16°F | 39.3 | 13 | April 17 |
| Athens | 52.0°F | 85°F | 18°F | 38.4 | – | April 19 |
| Minonk | 51.3°F | 86°F | 15°F | 37.6 | 22 | April 26 |
| Albion | 56.6°F | 89°F | 23°F | – | – | April 4 |
| Lacon | 52.6°F | 87°F | 18°F | 38.4 | 25 | April 20 |
| Princeville | 50.8°F | 86°F | 15°F | 38.8 | 20 | April 22 |
| Chenoa | 50.5°F | 84°F | 15°F | 36.3 | 20 | April 23 |
| Stockton | 47.8°F | 82°F | 12°F | 38.7 | 36 | April 27 |
| Cairo | 58.1°F | 89°F | 26°F | 51.0 | – | April 2 |
| Winchester | 52.9°F | 87°F | 18°F | 40.4 | – | April 18 |
| Grayville | 56.2°F | 89°F | 24°F | 50.0 | 12 | April 7 |
| Mount Carroll | 48.5°F | 85°F | 11°F | 40.3 | 33 | May 2 |
| Neoga | 53.6°F | 87°F | 19°F | 41.9 | – | April 16 |
| Walnut | 49.3°F | 83°F | 13°F | 36.8 | 36 | April 24 |
| Palestine | 55.1°F | 87°F | 23°F | 46.3 | 12 | April 12 |
| La Harpe | 50.8°F | 85°F | 15°F | 39.1 | – | April 21 |
| Windsor | 52.6°F | 85°F | 19°F | 41.2 | 14 | April 16 |
| Morrisonville | 53.6°F | 86°F | 19°F | 38.1 | 16 | April 12 |
| Rosiclare | 54.8°F | 86°F | 22°F | 50.9 | 3 | April 19 |
| Ramsey | 52.5°F | 85°F | 19°F | 42.5 | 13 | April 15 |
| Shabbona | 47.8°F | 82°F | 13°F | 37.4 | – | April 28 |
| Paw Paw | 47.8°F | 82°F | 12°F | 36.8 | 30 | April 27 |
| Hennepin | 51.4°F | 85°F | 17°F | 38.6 | – | April 18 |
| Piper City | 51.9°F | 88°F | 16°F | 44.4 | 25 | April 25 |
| Ogden | 52.2°F | 84°F | 18°F | 41.2 | 25 | April 20 |
| Brookport | 57.3°F | 89°F | 25°F | 49.1 | 3 | April 6 |
| Elizabeth | 47.5°F | 83°F | 10°F | 39.4 | 30 | May 1 |
| Brownstown | 54.6°F | 87°F | 21°F | 41.2 | – | April 3 |
| Avon | 49.3°F | 84°F | 13°F | 37.6 | 24 | April 22 |
| Golden | 52.0°F | 87°F | 16°F | – | – | April 18 |
| New Boston | 51.2°F | 86°F | 15°F | 36.3 | – | April 14 |
| Congerville | 52.0°F | 86°F | 17°F | 37.5 | 22 | April 21 |
| Sidell | 51.5°F | 84°F | 17°F | 40.4 | 24 | April 19 |
| Altona | 49.0°F | 83°F | 13°F | 39.4 | – | April 28 |
| Prairie City | 51.5°F | 86°F | 16°F | 38.5 | 21 | April 17 |
| Perry | 53.3°F | 87°F | 18°F | 39.1 | 21 | April 18 |
| Compton | 48.2°F | 83°F | 12°F | – | – | April 27 |
| Gladstone | 51.9°F | 86°F | 16°F | 37.2 | 17 | April 8 |
| Bentley | 52.8°F | 86°F | 18°F | 40.1 | 23 | April 13 |
| Kaskaskia | 56.4°F | 89°F | 24°F | 42.8 | 4 | April 8 |
| Illinois City | 50.4°F | 85°F | 13°F | 36.4 | – | April 18 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
What are Illinois's all-time weather records?
The official state records, reviewed by NOAA's State Climate Extremes Committee: from 117°F to −38°F.
| Record | Value | Where | When |
|---|---|---|---|
| Highest temperature | 117°F | East St. Louis | July 14, 1954 |
| Lowest temperature | −38°F | Mt. Carroll | January 31, 2019 |
| Most precipitation in 24 hours | 16.91 in | Aurora | July 18, 1996 |
| Most snow in 24 hours | 36 in | Astoria | February 28, 1900 |
| Deepest snow on the ground | 41 in | Gebhard Woods St.Pk. (tied 2 times; the latest shown) | January 31, 1979 |
Source: NOAA NCEI State Climate Extremes Committee records.
Which large cities in Illinois have no climate record of their own?
These 17 cities of 50,000 or more have no NOAA record with 1991-2020 normals under their own name; each page compares the nearest records, with their distance and elevation.
- Naperville153,124 people
- Cicero82,090 people
- Schaumburg77,099 people
- Evanston76,006 people
- Arlington Heights75,596 people
- Bolingbrook74,756 people
- Palatine65,951 people
- Skokie65,850 people
- Des Plaines58,832 people
- Orland Park58,020 people
- Oak Lawn56,531 people
- Mount Prospect55,460 people
- Berwyn55,152 people
- Tinley Park54,856 people
- Oak Park52,947 people
- Hoffman Estates50,920 people
- Downers Grove50,552 people
Which other NOAA stations in Illinois keep normals?
26 stations in Illinois that are not a town's own record keep 1991-2020 normals too: reservoirs and dams, parks and forests, research farms, remote sites and the second stations of towns (those are shown on the town's page). Each with its normal yearly mean:
- Cahokia56.2°F
- Carbondale Sewage Plant56.0°F
- Champaign (3 mi S)52.3°F
- Champaign (9 mi SW)51.1°F
- Chicago Aurora Municipal Airport49.4°F
- Chicago Botanic Garden49.6°F
- Chicago Midway Airport52.1°F
- Chicago Northerly Island50.8°F
- Chicago Waukegan Regional Airport48.3°F
- Decatur Water Treatment Plant53.0°F
- Dixon Springs Agricultural Center57.2°F
- Flora (5 mi NW)56.1°F
- Grand Chain Dam 5357.9°F
- Hennepin Water Treatment Plant51.0°F
- Iuka (12 mi SW)54.7°F
- Jacksonville (2 mi E)52.7°F
- Lawrenceville (2 mi WSW)54.9°F
- Little Red School House51.4°F
- Mattoon station53.6°F
- McHenry W.G. Stratton Lock and Dam48.6°F
- Monmouth (4 mi NW)50.0°F
- Newton (6 mi SSE)52.7°F
- Quincy Dam 2153.7°F
- Rend Lake Dam55.9°F
- Smithland Lock and Dam57.1°F
- Springfield #252.9°F
Source: NOAA NCEI 1991-2020 normals for each station.
Next
- Frost dates in IllinoisLast spring and first autumn frost at every station
- Every stateCompare the statewide normals
- Anna58.5°F a year, 51.1 in of precipitation
- Galena47.0°F a year, 39.6 in of precipitation
- Lake Villa48.6°F a year, 37.8 in of precipitation
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