Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
January | 23°F | 38°F | 29°F | 3.3" |
February | 24°F | 40°F | 31°F | 3.5" |
March | 36°F | 55°F | 44°F | 3.9" |
April | 45°F | 67°F | 55°F | 9.3" |
May | 55°F | 75°F | 64°F | 5.6" |
June | 64°F | 84°F | 73°F | 7.9" |
July | 66°F | 86°F | 76°F | 5.0" |
August | 65°F | 86°F | 74°F | 5.1" |
September | 57°F | 80°F | 67°F | 6.0" |
October | 46°F | 68°F | 56°F | 5.6" |
November | 36°F | 54°F | 44°F | 3.6" |
December | 28°F | 42°F | 34°F | 3.6" |
Index | Williamson | Illinois | National |
Air quality index | 54 | 41 | 42 |
Pollution index | 647,280 | 3,148,694 | 2,726,193 |
Measurement | Total |
Days measured | 365 |
Days with good air quality | 134 |
Days with moderate air quality | 221 |
Days w/ poor A.Q. for sensitive groups | 8 |
Days with unhealthy air quality | 2 |
Pollutant | Total |
Arsenic | 0.001% |
Benzene | 0.020% |
Carbon Tetrachloride | 0.000% |
Lead | 0.000% |
Mercury | 0.000% |
City | Population | Air Quality Index | National Avg. |
Butler, IL | 269 | 40 | 20.0% |
Litchfield, IL | 6,626 | 40 | 20.0% |
Taylor Springs, IL | 587 | 40 | 20.0% |
Royal Lakes, IL | 282 | 54 | 8.0% |
Panama, IL | 221 | 54 | 8.0% |
Williamson, IL | 202 | 54 | 8.0% |
City | Population | Air Quality Index | National Avg. |
Fairford, AL | 202 | 42 | 16.0% |
Ratcliff, AR | 202 | 36 | 28.0% |
Carrizo, AZ | 202 | 44 | 12.0% |
Greenhorn, CA | 202 | 44 | 12.0% |
Alpine, CO | 202 | 44 | 12.0% |
Williamson, IL | 202 | 54 | 8.0% |