| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 9°F | 30°F | 20°F | 2.9" |
| February | 12°F | 32°F | 22°F | 2.5" |
| March | 21°F | 41°F | 31°F | 3.6" |
| April | 34°F | 56°F | 45°F | 4.7" |
| May | 44°F | 65°F | 54°F | 3.6" |
| June | 54°F | 74°F | 63°F | 5.5" |
| July | 59°F | 80°F | 69°F | 4.6" |
| August | 56°F | 78°F | 66°F | 3.5" |
| September | 49°F | 71°F | 60°F | 4.0" |
| October | 39°F | 58°F | 48°F | 7.6" |
| November | 30°F | 48°F | 39°F | 5.7" |
| December | 17°F | 35°F | 26°F | 3.8" |
| Index | Dexter | Maine | National |
| Air quality index | 31 | 33 | 42 |
| Pollution index | 3,063,530 | 3,417,521 | 2,726,193 |
| Measurement | Total |
| Days measured | 361 |
| Days with good air quality | 348 |
| Days with moderate air quality | 13 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.004% |
| City | Population | Air Quality Index | National Avg. |
| Hartland, ME | 547 | 31 | 38.0% |
| Newport, ME | 1,949 | 31 | 38.0% |
| Dover-Foxcroft, ME | 2,574 | 31 | 38.0% |
| Guilford, ME | 511 | 31 | 38.0% |
| Dexter, ME | 2,045 | 31 | 38.0% |
| City | Population | Air Quality Index | National Avg. |
| Morris, AL | 2,045 | 53 | 6.0% |
| Hickman, KY | 2,045 | 26 | 48.0% |
| Long Beach, MD | 2,045 | 41 | 18.0% |
| Crow Agency, MT | 2,045 | 21 | 58.0% |
| Edisto, SC | 2,045 | 43 | 14.0% |
| Dexter, ME | 2,045 | 31 | 38.0% |