| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 19°F | 39°F | 29°F | 3.1" |
| February | 18°F | 40°F | 29°F | 2.8" |
| March | 27°F | 48°F | 37°F | 3.2" |
| April | 37°F | 61°F | 49°F | 3.7" |
| May | 46°F | 71°F | 59°F | 3.4" |
| June | 55°F | 79°F | 67°F | 4.5" |
| July | 61°F | 85°F | 73°F | 3.6" |
| August | 57°F | 83°F | 71°F | 3.6" |
| September | 51°F | 77°F | 64°F | 3.2" |
| October | 41°F | 66°F | 53°F | 4.9" |
| November | 32°F | 55°F | 43°F | 3.6" |
| December | 25°F | 45°F | 34°F | 4.0" |
| Index | Dedham | Massachusetts | National |
| Air quality index | 43 | 40 | 42 |
| Pollution index | 7,556,320 | 8,399,610 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 291 |
| Days with moderate air quality | 73 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.070% |
| Carbon Tetrachloride | 0.040% |
| Lead | 0.010% |
| Mercury | 0.040% |
| City | Population | Air Quality Index | National Avg. |
| Maynard, MA | 10,900 | 40 | 20.0% |
| Framingham, MA | 72,846 | 40 | 20.0% |
| Braintree Town, MA | 37,196 | 43 | 14.0% |
| Hingham, MA | 5,837 | 43 | 14.0% |
| Millis-Clicquot, MA | 4,455 | 43 | 14.0% |
| Dedham, MA | 25,330 | 43 | 14.0% |
| City | Population | Air Quality Index | National Avg. |
| Edwardsville, IL | 25,332 | 54 | 8.0% |
| Candiac, QC | 25,341 | n/a | |
| Kingsville, TX | 25,367 | 30 | 40.0% |
| Clinton, IA | 25,290 | 42 | 16.0% |
| Mount Pleasant, MI | 25,290 | 26 | 48.0% |
| Dedham, MA | 25,330 | 43 | 14.0% |
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