| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 15°F | 36°F | 24°F | 1.5" |
| February | 15°F | 35°F | 24°F | 2.3" |
| March | 30°F | 51°F | 39°F | 3.5" |
| April | 41°F | 65°F | 52°F | 8.7" |
| May | 52°F | 74°F | 62°F | 7.1" |
| June | 62°F | 83°F | 72°F | 5.9" |
| July | 66°F | 87°F | 76°F | 7.3" |
| August | 63°F | 84°F | 72°F | 7.4" |
| September | 54°F | 77°F | 64°F | 10.8" |
| October | 43°F | 66°F | 53°F | 4.9" |
| November | 30°F | 50°F | 39°F | 4.4" |
| December | 22°F | 39°F | 30°F | 4.0" |
| Index | Le Roy | Iowa | National |
| Air quality index | 39 | 39 | 42 |
| Pollution index | 376,148 | 1,154,535 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 306 |
| Days with moderate air quality | 59 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.001% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Leon, IA | 1,883 | 39 | 22.0% |
| Van Wert, IA | 137 | 39 | 22.0% |
| Osceola, IA | 5,160 | 39 | 22.0% |
| Allerton, IA | 453 | 39 | 22.0% |
| Garden Grove, IA | 203 | 39 | 22.0% |
| Le Roy, IA | 1 | 39 | 22.0% |
| City | Population | Air Quality Index | National Avg. |
| Drummond, ID | 1 | 43 | 14.0% |
| Weeki Wachee, FL | 1 | 30 | 40.0% |
| Clear Hills 152C, AB | 1 | n/a | |
| Mont-Valin, QC | 1 | n/a | |
| Réservoir-Dozois, QC | 1 | n/a | |
| Le Roy, IA | 1 | 39 | 22.0% |
Here are the best places to live in Iowa
Check out the 10 most dangerous cities in Iowa
Most Dangerous Cities In The US
Check out the 10 safest cities in Iowa