NOAA's National Centers for Environmental Information
County Mapping
County Average Temperature
October - December 1999
0°F10°F20°F30°F40°F50°F60°F70°F80°F90°F
Illinois (Hover over a County)
TempAverage Temperature: 45.2°F
Rank: 14th Warmest
Anomaly: 3.5°F
Mean: 41.6°F
County | Value | Rank 130 Years | Anomaly | 1901- |
|---|---|---|---|---|
| Adams County | 45.9°F | 119 | 3.7°F | 42.2°F |
| Alexander County | 50.3°F | 119 | 3.3°F | 47.1°F |
| Bond County | 48.0°F | 121 | 3.8°F | 44.1°F |
| Boone County | 40.3°F | 109 | 3.1°F | 37.2°F |
| Brown County | 45.5°F | 115 | 3.5°F | 42.0°F |
| Bureau County | 42.1°F | 114 | 3.4°F | 38.6°F |
| Calhoun County | 47.7°F | 120 | 3.9°F | 43.8°F |
| Carroll County | 40.5°F | 116 | 3.4°F | 37.0°F |
| Cass County | 45.7°F | 118 | 3.6°F | 42.0°F |
| Champaign County | 44.3°F | 113 | 3.4°F | 40.9°F |
| Christian County | 46.3°F | 119 | 3.9°F | 42.5°F |
| Clark County | 46.3°F | 114 | 3.4°F | 42.9°F |
| Clay County | 47.8°F | 120 | 3.7°F | 44.0°F |
| Clinton County | 48.6°F | 122 | 3.8°F | 44.7°F |
| Coles County | 45.9°F | 116 | 3.6°F | 42.3°F |
| Cook County | 42.8°F | 113 | 3.3°F | 39.5°F |
| Crawford County | 47.4°F | 119 | 3.7°F | 43.8°F |
| Cumberland County | 46.7°F | 119 | 3.8°F | 42.9°F |
| DeKalb County | 40.8°F | 110 | 3.0°F | 37.8°F |
| De Witt County | 44.4°F | 115 | 3.6°F | 40.8°F |
| Douglas County | 45.2°F | 116 | 3.5°F | 41.7°F |
| DuPage County | 42.1°F | 114 | 3.3°F | 38.8°F |
| Edgar County | 45.5°F | 114 | 3.5°F | 42.0°F |
| Edwards County | 49.0°F | 119 | 3.8°F | 45.1°F |
| Effingham County | 47.2°F | 121 | 4.0°F | 43.2°F |
| Fayette County | 47.4°F | 120 | 3.8°F | 43.6°F |
| Ford County | 43.5°F | 115 | 3.4°F | 40.1°F |
| Franklin County | 48.6°F | 116 | 3.1°F | 45.5°F |
| Fulton County | 44.4°F | 115 | 3.3°F | 41.1°F |
| Gallatin County | 50.0°F | 123 | 3.6°F | 46.4°F |
| Greene County | 47.1°F | 118 | 3.6°F | 43.5°F |
| Grundy County | 42.6°F | 114 | 3.4°F | 39.3°F |
| Hamilton County | 48.8°F | 118 | 3.4°F | 45.4°F |
| Hancock County | 45.1°F | 118 | 3.7°F | 41.4°F |
| Hardin County | 50.3°F | 122 | 3.6°F | 46.7°F |
| Henderson County | 43.9°F | 113 | 3.6°F | 40.3°F |
| Henry County | 42.2°F | 111 | 3.4°F | 38.9°F |
| Iroquois County | 43.4°F | 115 | 3.4°F | 40.1°F |
| Jackson County | 49.1°F | 122 | 3.5°F | 45.6°F |
| Jasper County | 47.5°F | 122 | 4.0°F | 43.5°F |
| Jefferson County | 48.3°F | 119 | 3.3°F | 45.0°F |
| Jersey County | 48.0°F | 122 | 3.9°F | 44.1°F |
| Jo Daviess County | 39.9°F | 114 | 3.3°F | 36.6°F |
| Johnson County | 49.9°F | 123 | 3.5°F | 46.4°F |
| Kane County | 41.2°F | 110 | 3.0°F | 38.2°F |
| Kankakee County | 43.1°F | 113 | 3.4°F | 39.7°F |
| Kendall County | 42.3°F | 114 | 3.3°F | 39.0°F |
| Knox County | 43.0°F | 111 | 3.4°F | 39.6°F |
| Lake County | 41.6°F | 115 | 3.2°F | 38.4°F |
| LaSalle County | 42.2°F | 114 | 3.2°F | 39.0°F |
| Lawrence County | 48.1°F | 119 | 3.6°F | 44.5°F |
| Lee County | 40.9°F | 111 | 3.1°F | 37.8°F |
| Livingston County | 43.1°F | 114 | 3.5°F | 39.6°F |
| Logan County | 45.0°F | 117 | 3.6°F | 41.4°F |
| McDonough County | 44.4°F | 116 | 3.6°F | 40.8°F |
| McHenry County | 40.5°F | 110 | 3.2°F | 37.3°F |
| McLean County | 43.8°F | 116 | 3.8°F | 39.9°F |
| Macon County | 45.3°F | 116 | 3.6°F | 41.7°F |
| Macoupin County | 47.2°F | 121 | 4.0°F | 43.2°F |
| Madison County | 48.8°F | 123 | 4.1°F | 44.7°F |
| Marion County | 47.9°F | 121 | 3.6°F | 44.3°F |
| Marshall County | 43.3°F | 115 | 3.7°F | 39.6°F |
| Mason County | 45.1°F | 115 | 3.3°F | 41.8°F |
| Massac County | 50.7°F | 122 | 3.5°F | 47.2°F |
| Menard County | 45.3°F | 113 | 3.4°F | 41.9°F |
| Mercer County | 42.8°F | 112 | 3.4°F | 39.4°F |
| Monroe County | 49.8°F | 124 | 4.2°F | 45.6°F |
| Montgomery County | 47.1°F | 121 | 4.0°F | 43.1°F |
| Morgan County | 45.9°F | 119 | 3.7°F | 42.2°F |
| Moultrie County | 45.8°F | 118 | 3.8°F | 42.0°F |
| Ogle County | 40.6°F | 113 | 3.2°F | 37.3°F |
| Peoria County | 43.8°F | 117 | 3.7°F | 40.2°F |
| Perry County | 49.0°F | 124 | 3.7°F | 45.2°F |
| Piatt County | 44.4°F | 112 | 3.3°F | 41.1°F |
| Pike County | 46.4°F | 117 | 3.5°F | 42.8°F |
| Pope County | 50.2°F | 122 | 3.6°F | 46.7°F |
| Pulaski County | 50.5°F | 120 | 3.3°F | 47.2°F |
| Putnam County | 43.0°F | 114 | 3.5°F | 39.5°F |
| Randolph County | 49.6°F | 126 | 4.2°F | 45.4°F |
| Richland County | 48.1°F | 119 | 3.7°F | 44.4°F |
| Rock Island County | 42.5°F | 113 | 3.4°F | 39.0°F |
| St. Clair County | 49.6°F | 125 | 4.3°F | 45.3°F |
| Saline County | 49.6°F | 122 | 3.6°F | 46.0°F |
| Sangamon County | 45.9°F | 118 | 3.6°F | 42.2°F |
| Schuyler County | 45.4°F | 120 | 3.8°F | 41.6°F |
| Scott County | 46.2°F | 115 | 3.4°F | 42.8°F |
| Shelby County | 46.5°F | 119 | 3.9°F | 42.6°F |
| Stark County | 42.5°F | 112 | 3.3°F | 39.2°F |
| Stephenson County | 40.0°F | 115 | 3.5°F | 36.5°F |
| Tazewell County | 44.4°F | 119 | 3.8°F | 40.6°F |
| Union County | 49.6°F | 120 | 3.5°F | 46.2°F |
| Vermilion County | 44.3°F | 111 | 3.1°F | 41.2°F |
| Wabash County | 48.7°F | 118 | 3.5°F | 45.2°F |
| Warren County | 43.2°F | 111 | 3.4°F | 39.8°F |
| Washington County | 48.9°F | 123 | 3.9°F | 44.9°F |
| Wayne County | 48.5°F | 119 | 3.6°F | 44.9°F |
| White County | 49.4°F | 119 | 3.6°F | 45.8°F |
| Whiteside County | 41.2°F | 111 | 3.1°F | 38.1°F |
| Will County | 42.9°F | 113 | 3.3°F | 39.5°F |
| Williamson County | 49.1°F | 120 | 3.3°F | 45.8°F |
| Winnebago County | 40.4°F | 110 | 3.2°F | 37.2°F |
| Woodford County | 43.6°F | 118 | 4.1°F | 39.6°F |
Citing This Page
- NOAA National Centers for Environmental information, Climate at a Glance: County Mapping, published July 2025, retrieved on July 12, 2025 from https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping
