| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 9°F | 24°F | 16°F | 0.8" |
| February | 11°F | 28°F | 18°F | 1.4" |
| March | 26°F | 44°F | 33°F | 2.1" |
| April | 37°F | 58°F | 46°F | 3.5" |
| May | 48°F | 70°F | 58°F | 5.7" |
| June | 58°F | 79°F | 68°F | 5.6" |
| July | 62°F | 83°F | 72°F | 5.9" |
| August | 59°F | 79°F | 69°F | 6.5" |
| September | 52°F | 74°F | 61°F | 4.8" |
| October | 39°F | 60°F | 48°F | 7.9" |
| November | 26°F | 45°F | 34°F | 2.6" |
| December | 12°F | 27°F | 19°F | 0.7" |
| Index | Windom | Minnesota | National |
| Air quality index | 32 | 35 | 42 |
| Pollution index | 1,563,560 | 1,854,519 | 2,726,193 |
| Measurement | Total |
| Days measured | 362 |
| Days with good air quality | 327 |
| Days with moderate air quality | 35 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Okabena, MN | 215 | 32 | 36.0% |
| Fish Lake, MN | 56 | 32 | 36.0% |
| Heron Lake, MN | 729 | 32 | 36.0% |
| Darfur, MN | 73 | 32 | 36.0% |
| Jeffers, MN | 353 | 32 | 36.0% |
| Windom, MN | 4,584 | 32 | 36.0% |
| City | Population | Air Quality Index | National Avg. |
| Armona, CA | 4,584 | 56 | 12.0% |
| California, MO | 4,585 | 39 | 22.0% |
| Winnfield, LA | 4,586 | 30 | 40.0% |
| Port Hardy, BC | 4,586 | n/a | |
| Blood 148, AB | 4,581 | n/a | |
| Windom, MN | 4,584 | 32 | 36.0% |