| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 17°F | 36°F | 26°F | 3.0" |
| February | 17°F | 38°F | 27°F | 2.8" |
| March | 26°F | 47°F | 36°F | 3.4" |
| April | 37°F | 63°F | 49°F | 4.1" |
| May | 47°F | 73°F | 59°F | 4.0" |
| June | 56°F | 80°F | 68°F | 5.8" |
| July | 62°F | 86°F | 73°F | 4.8" |
| August | 59°F | 84°F | 71°F | 4.4" |
| September | 53°F | 77°F | 64°F | 3.7" |
| October | 42°F | 65°F | 52°F | 5.9" |
| November | 31°F | 53°F | 41°F | 3.0" |
| December | 23°F | 41°F | 32°F | 4.2" |
| Index | Blandford | 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. |
| Chester, MA | 970 | 37 | 26.0% |
| Norfolk, CT | 653 | 37 | 26.0% |
| Suffield Depot, CT | 2,068 | 40 | 20.0% |
| Huntington, MA | 698 | 40 | 20.0% |
| Westfield, MA | 42,547 | 40 | 20.0% |
| Blandford, MA | 349 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| St. Marks, FL | 349 | 40 | 20.0% |
| Keysville, GA | 349 | 47 | 6.0% |
| Montrose, GA | 349 | 38 | 24.0% |
| Duncombe, IA | 349 | 37 | 26.0% |
| Kempton, IN | 349 | 42 | 16.0% |
| Blandford, MA | 349 | 40 | 20.0% |