| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 6°F | 24°F | 15°F | 1.2" |
| February | 10°F | 30°F | 20°F | 0.6" |
| March | 24°F | 44°F | 34°F | 1.9" |
| April | 35°F | 56°F | 44°F | 3.4" |
| May | 45°F | 70°F | 57°F | 4.9" |
| June | 54°F | 77°F | 65°F | 9.5" |
| July | 62°F | 84°F | 73°F | 7.0" |
| August | 58°F | 81°F | 69°F | 12.0" |
| September | 45°F | 69°F | 56°F | 6.2" |
| October | 37°F | 59°F | 47°F | 13.6" |
| November | 27°F | 44°F | 35°F | 2.2" |
| December | 12°F | 28°F | 20°F | 3.2" |
| Index | McGrath | Minnesota | National |
| Air quality index | 29 | 35 | 42 |
| Pollution index | 1,227,690 | 1,854,519 | 2,726,193 |
| Measurement | Total |
| Days measured | 359 |
| Days with good air quality | 328 |
| Days with moderate air quality | 29 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.010% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Wahkon, MN | 296 | 29 | 42.0% |
| Isle, MN | 726 | 29 | 42.0% |
| McGrath, MN | 33 | 29 | 42.0% |
| City | Population | Air Quality Index | National Avg. |
| Nanafalia, AL | 33 | 36 | 28.0% |
| Rye, AZ | 33 | 60 | 20.0% |
| Creston, CA | 33 | 46 | 8.0% |
| Jenner, CA | 33 | 34 | 32.0% |
| Moss Landing, CA | 33 | 37 | 26.0% |
| McGrath, MN | 33 | 29 | 42.0% |