| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 10°F | 25°F | 17°F | 0.5" |
| February | 13°F | 29°F | 20°F | 0.7" |
| March | 26°F | 44°F | 34°F | 1.6" |
| April | 39°F | 59°F | 48°F | 3.9" |
| May | 49°F | 71°F | 59°F | 4.5" |
| June | 60°F | 80°F | 70°F | 5.7" |
| July | 65°F | 85°F | 75°F | 4.4" |
| August | 62°F | 82°F | 72°F | 5.8" |
| September | 55°F | 75°F | 64°F | 3.4" |
| October | 42°F | 60°F | 50°F | 3.2" |
| November | 29°F | 46°F | 37°F | 1.4" |
| December | 15°F | 29°F | 21°F | 1.2" |
| Index | Stillwater | Minnesota | National |
| Air quality index | 46 | 35 | 42 |
| Pollution index | 2,108,790 | 1,854,519 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 214 |
| Days with moderate air quality | 148 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.003% |
| Benzene | 0.040% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.001% |
| Mercury | 0.003% |
| City | Population | Air Quality Index | National Avg. |
| River Falls, WI | 16,442 | 37 | 26.0% |
| Roberts, WI | 1,889 | 37 | 26.0% |
| St. Marys Point, MN | 453 | 37 | 26.0% |
| St. Paul, MN | 315,338 | 46 | 8.0% |
| Gem Lake, MN | 540 | 46 | 8.0% |
| Stillwater, MN | 20,207 | 46 | 8.0% |
| City | Population | Air Quality Index | National Avg. |
| Rivière-du-Loup, QC | 20,207 | n/a | |
| West Mifflin, PA | 20,208 | 56 | 12.0% |
| Seymour, IN | 20,201 | 35 | 30.0% |
| North Bay Shore, NY | 20,198 | 43 | 14.0% |
| Upper St. Clair, PA | 20,221 | 56 | 12.0% |
| Stillwater, MN | 20,207 | 46 | 8.0% |