NOAA's National Centers for Environmental Information
County Mapping
County Average Temperature
October - December 1940
0°F10°F20°F30°F40°F50°F60°F70°F80°F90°F
Illinois (Hover over a County)
Temp
Average Temperature
:
--
Anomaly:
--
Rank:
-- Coldest
Mean:
--
*Signifies a tie
**Insufficient variability in the data record renders rank insignificant
County
|
Value | Anomaly | Rank 130 Years | 1901- |
|---|---|---|---|---|
| Adams County | 44.5°F | 2.3°F | 104 | 42.2°F |
| Alexander County | 49.5°F | 2.4°F | 111 | 47.1°F |
| Bond County | 46.7°F | 2.5°F | 108 | 44.1°F |
| Boone County | 38.4°F | 1.2°F | 84 | 37.2°F |
| Brown County | 44.1°F | 2.1°F | 103 | 42.0°F |
| Bureau County | 40.0°F | 1.4°F | 88 | 38.6°F |
| Calhoun County | 45.9°F | 2.1°F | 102 | 43.8°F |
| Carroll County | 38.1°F | 1.1°F | 83 | 37.0°F |
| Cass County | 44.0°F | 2.0°F | 100 | 42.0°F |
| Champaign County | 43.3°F | 2.4°F | 102 | 40.9°F |
| Christian County | 44.6°F | 2.1°F | 103 | 42.5°F |
| Clark County | 45.2°F | 2.4°F | 105 | 42.9°F |
| Clay County | 46.7°F | 2.7°F | 110 | 44.0°F |
| Clinton County | 47.4°F | 2.7°F | 109 | 44.7°F |
| Coles County | 44.7°F | 2.4°F | 105 | 42.3°F |
| Cook County | 40.9°F | 1.4°F | 85 | 39.5°F |
| Crawford County | 46.3°F | 2.6°F | 105 | 43.8°F |
| Cumberland County | 45.3°F | 2.4°F | 106 | 42.9°F |
| DeKalb County | 39.0°F | 1.2°F | 83 | 37.8°F |
| De Witt County | 42.6°F | 1.8°F | 96 | 40.8°F |
| Douglas County | 44.3°F | 2.6°F | 104 | 41.7°F |
| DuPage County | 40.2°F | 1.4°F | 85 | 38.8°F |
| Edgar County | 44.4°F | 2.4°F | 104 | 42.0°F |
| Edwards County | 48.1°F | 2.9°F | 113 | 45.1°F |
| Effingham County | 45.6°F | 2.5°F | 104 | 43.2°F |
| Fayette County | 45.9°F | 2.3°F | 104 | 43.6°F |
| Ford County | 41.8°F | 1.7°F | 93 | 40.1°F |
| Franklin County | 48.4°F | 2.9°F | 112 | 45.5°F |
| Fulton County | 43.2°F | 2.1°F | 103 | 41.1°F |
| Gallatin County | 49.1°F | 2.8°F | 113 | 46.4°F |
| Greene County | 45.8°F | 2.3°F | 106 | 43.5°F |
| Grundy County | 40.5°F | 1.2°F | 81 | 39.3°F |
| Hamilton County | 48.4°F | 3.0°F | 113 | 45.4°F |
| Hancock County | 43.7°F | 2.3°F | 104 | 41.4°F |
| Hardin County | 49.5°F | 2.8°F | 112 | 46.7°F |
| Henderson County | 42.4°F | 2.1°F | 104 | 40.3°F |
| Henry County | 40.7°F | 1.8°F | 93 | 38.9°F |
| Iroquois County | 41.7°F | 1.6°F | 95 | 40.1°F |
| Jackson County | 48.3°F | 2.7°F | 111 | 45.6°F |
| Jasper County | 46.2°F | 2.6°F | 108 | 43.5°F |
| Jefferson County | 47.8°F | 2.8°F | 111 | 45.0°F |
| Jersey County | 46.3°F | 2.2°F | 104 | 44.1°F |
| Jo Daviess County | 37.1°F | 0.6°F | 75 | 36.6°F |
| Johnson County | 49.1°F | 2.7°F | 114 | 46.4°F |
| Kane County | 39.5°F | 1.4°F | 86 | 38.2°F |
| Kankakee County | 41.2°F | 1.5°F | 88 | 39.7°F |
| Kendall County | 40.3°F | 1.3°F | 84 | 39.0°F |
| Knox County | 41.6°F | 1.9°F | 98 | 39.6°F |
| Lake County | 39.6°F | 1.2°F | 83 | 38.4°F |
| LaSalle County | 40.2°F | 1.2°F | 84 | 39.0°F |
| Lawrence County | 47.4°F | 2.8°F | 111 | 44.5°F |
| Lee County | 38.9°F | 1.1°F | 82 | 37.8°F |
| Livingston County | 41.2°F | 1.6°F | 90 | 39.6°F |
| Logan County | 43.4°F | 2.0°F | 101 | 41.4°F |
| McDonough County | 43.0°F | 2.1°F | 103 | 40.8°F |
| McHenry County | 38.4°F | 1.1°F | 82 | 37.3°F |
| McLean County | 41.3°F | 1.4°F | 89 | 39.9°F |
| Macon County | 43.9°F | 2.2°F | 102 | 41.7°F |
| Macoupin County | 45.7°F | 2.5°F | 108 | 43.2°F |
| Madison County | 47.3°F | 2.6°F | 106 | 44.7°F |
| Marion County | 46.9°F | 2.6°F | 110 | 44.3°F |
| Marshall County | 41.1°F | 1.6°F | 89 | 39.6°F |
| Mason County | 44.0°F | 2.2°F | 104 | 41.8°F |
| Massac County | 49.6°F | 2.4°F | 106 | 47.2°F |
| Menard County | 44.1°F | 2.1°F | 103 | 41.9°F |
| Mercer County | 41.6°F | 2.2°F | 102 | 39.4°F |
| Monroe County | 48.1°F | 2.5°F | 107 | 45.6°F |
| Montgomery County | 45.4°F | 2.3°F | 104 | 43.1°F |
| Morgan County | 44.3°F | 2.1°F | 101 | 42.2°F |
| Moultrie County | 44.4°F | 2.4°F | 105 | 42.0°F |
| Ogle County | 38.3°F | 1.0°F | 82 | 37.3°F |
| Peoria County | 42.1°F | 2.0°F | 94 | 40.2°F |
| Perry County | 47.9°F | 2.7°F | 109 | 45.2°F |
| Piatt County | 43.5°F | 2.4°F | 102 | 41.1°F |
| Pike County | 45.3°F | 2.4°F | 106 | 42.8°F |
| Pope County | 49.3°F | 2.6°F | 112 | 46.7°F |
| Pulaski County | 49.7°F | 2.5°F | 112 | 47.2°F |
| Putnam County | 40.9°F | 1.4°F | 87 | 39.5°F |
| Randolph County | 47.8°F | 2.4°F | 107 | 45.4°F |
| Richland County | 47.3°F | 2.9°F | 112 | 44.4°F |
| Rock Island County | 41.1°F | 2.0°F | 96 | 39.0°F |
| St. Clair County | 47.9°F | 2.6°F | 105 | 45.3°F |
| Saline County | 49.0°F | 3.0°F | 113 | 46.0°F |
| Sangamon County | 44.4°F | 2.2°F | 103 | 42.2°F |
| Schuyler County | 43.5°F | 1.9°F | 98 | 41.6°F |
| Scott County | 45.0°F | 2.2°F | 105 | 42.8°F |
| Shelby County | 44.9°F | 2.3°F | 105 | 42.6°F |
| Stark County | 41.0°F | 1.8°F | 94 | 39.2°F |
| Stephenson County | 37.5°F | 1.0°F | 83 | 36.5°F |
| Tazewell County | 42.3°F | 1.7°F | 93 | 40.6°F |
| Union County | 48.8°F | 2.6°F | 111 | 46.2°F |
| Vermilion County | 43.4°F | 2.2°F | 102 | 41.2°F |
| Wabash County | 48.0°F | 2.8°F | 112 | 45.2°F |
| Warren County | 41.8°F | 2.0°F | 101 | 39.8°F |
| Washington County | 47.5°F | 2.6°F | 109 | 44.9°F |
| Wayne County | 47.8°F | 2.9°F | 110 | 44.9°F |
| White County | 48.6°F | 2.8°F | 111 | 45.8°F |
| Whiteside County | 39.5°F | 1.4°F | 87 | 38.1°F |
| Will County | 40.8°F | 1.3°F | 86 | 39.5°F |
| Williamson County | 48.6°F | 2.8°F | 111 | 45.8°F |
| Winnebago County | 38.3°F | 1.1°F | 83 | 37.2°F |
| Woodford County | 41.1°F | 1.5°F | 88 | 39.6°F |
Citing This Page
- NOAA National Centers for Environmental information, Climate at a Glance: County Mapping, published July 2025, retrieved on August 3, 2025 from https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping
