| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 14°F | 30°F | 22°F | 2.3" |
| February | 14°F | 31°F | 23°F | 2.8" |
| March | 26°F | 45°F | 35°F | 3.7" |
| April | 36°F | 58°F | 46°F | 5.9" |
| May | 46°F | 71°F | 58°F | 4.8" |
| June | 56°F | 79°F | 67°F | 7.8" |
| July | 59°F | 82°F | 70°F | 11.4" |
| August | 57°F | 81°F | 68°F | 5.4" |
| September | 50°F | 74°F | 61°F | 7.1" |
| October | 40°F | 61°F | 50°F | 5.8" |
| November | 29°F | 48°F | 38°F | 5.2" |
| December | 19°F | 34°F | 27°F | 3.3" |
| Index | Richmond | Illinois | National |
| Air quality index | 39 | 41 | 50 |
| Pollution index | 4,811,660 | 3,347,295 | 5,066,862 |
| Measurement | Total |
| Days measured | 203 |
| Days with good air quality | 174 |
| Days with moderate air quality | 28 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.004% |
| Benzene | 0.080% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.040% |
| Mercury | 0.010% |
| City, State | Population | Air Quality Index | National Avg. |
| Greenwood, IL | 425 | 37 | 26% |
| Bloomfield, WI | 4,700 | 37 | 26% |
| Elkhorn, WI | 9,931 | 37 | 26% |
| Fontana-on-Geneva Lake, WI | 1,636 | 37 | 26% |
| Hebron, IL | 1,288 | 37 | 26% |
| Richmond, IL | 2,038 | 39 | 22% |
| City, State | Population | Air Quality Index | National Avg. |
| Victoria, VA | 2,038 | 44 | 12% |
| Lavonia, GA | 2,038 | 41 | 18% |
| Crow Agency, MT | 2,038 | 21 | 58% |
| Hillsborough, NH | 2,037 | 27 | 46% |
| St. Bonaventure, NY | 2,037 | 9 | 82% |
| Richmond, IL | 2,038 | 39 | 22% |
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