| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 10°F | 25°F | 17°F | 0.5" |
| February | 12°F | 27°F | 19°F | 0.7" |
| March | 26°F | 42°F | 33°F | 1.9" |
| April | 38°F | 57°F | 46°F | 3.6" |
| May | 49°F | 69°F | 58°F | 4.3" |
| June | 59°F | 78°F | 67°F | 4.7" |
| July | 62°F | 81°F | 71°F | 2.9" |
| August | 60°F | 79°F | 69°F | 2.9" |
| September | 53°F | 73°F | 62°F | 4.0" |
| October | 41°F | 60°F | 49°F | 3.1" |
| November | 29°F | 45°F | 36°F | 1.4" |
| December | 16°F | 29°F | 22°F | 1.4" |
| Index | Le Roy | Minnesota | National |
| Air quality index | 36 | 35 | 42 |
| Pollution index | 1,320,050 | 1,854,519 | 2,726,193 |
| Measurement | Total |
| Days measured | 364 |
| Days with good air quality | 313 |
| Days with moderate air quality | 51 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.040% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Meyer, IA | 13 | 15 | 70.0% |
| Stacyville, IA | 520 | 15 | 70.0% |
| McIntire, IA | 83 | 15 | 70.0% |
| Little Cedar, IA | 28 | 15 | 70.0% |
| Riceville, IA | 891 | 15 | 70.0% |
| Le Roy, MN | 1,040 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Chalfant, CA | 1,040 | 47 | 6.0% |
| Ellicott, CO | 1,040 | 45 | 10.0% |
| George, IA | 1,040 | 36 | 28.0% |
| Sidney, IA | 1,040 | 40 | 20.0% |
| Plain Dealing, LA | 1,040 | 39 | 22.0% |
| Le Roy, MN | 1,040 | 36 | 28.0% |