| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 16°F | 36°F | 27°F | 5.4" |
| February | 16°F | 38°F | 27°F | 5.5" |
| March | 26°F | 48°F | 37°F | 6.7" |
| April | 36°F | 62°F | 49°F | 5.7" |
| May | 46°F | 73°F | 60°F | 6.3" |
| June | 55°F | 79°F | 67°F | 7.6" |
| July | 61°F | 85°F | 73°F | 7.3" |
| August | 58°F | 83°F | 71°F | 8.2" |
| September | 51°F | 77°F | 64°F | 7.9" |
| October | 41°F | 65°F | 52°F | 8.1" |
| November | 30°F | 53°F | 41°F | 5.8" |
| December | 23°F | 41°F | 32°F | 6.5" |
| Index | Monson Center | Massachusetts | National |
| Air quality index | 40 | 40 | 42 |
| Pollution index | 7,859,360 | 8,399,610 | 2,726,193 |
| Measurement | Total |
| Days measured | 364 |
| Days with good air quality | 305 |
| Days with moderate air quality | 59 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.030% |
| Benzene | 0.070% |
| Carbon Tetrachloride | 0.030% |
| Lead | 0.320% |
| Mercury | 0.070% |
| City | Population | Air Quality Index | National Avg. |
| Somers, CT | 2,403 | 40 | 20.0% |
| Longmeadow, MA | 16,275 | 40 | 20.0% |
| Palmer Town, MA | 12,662 | 40 | 20.0% |
| Brookfield, MA | 739 | 40 | 20.0% |
| Warren, MA | 563 | 40 | 20.0% |
| Monson Center, MA | 1,754 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Lacoochee, FL | 1,754 | 36 | 28.0% |
| Guttenberg, IA | 1,754 | 29 | 42.0% |
| Chenoweth, OR | 1,754 | 23 | 54.0% |
| Depoe Bay, OR | 1,754 | 17 | 66.0% |
| Willard, UT | 1,754 | 44 | 12.0% |
| Monson Center, MA | 1,754 | 40 | 20.0% |