| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 7°F | 24°F | 16°F | 3.4" |
| February | 8°F | 25°F | 16°F | 3.0" |
| March | 16°F | 35°F | 25°F | 3.5" |
| April | 30°F | 49°F | 39°F | 4.0" |
| May | 42°F | 63°F | 52°F | 4.3" |
| June | 51°F | 70°F | 60°F | 5.7" |
| July | 58°F | 76°F | 66°F | 4.2" |
| August | 56°F | 74°F | 64°F | 5.0" |
| September | 49°F | 67°F | 57°F | 3.5" |
| October | 38°F | 54°F | 46°F | 6.1" |
| November | 27°F | 41°F | 34°F | 4.2" |
| December | 14°F | 28°F | 21°F | 5.6" |
| Index | Guilford | 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. |
| Dexter, ME | 1,981 | 31 | 38.0% |
| Dover-Foxcroft, ME | 2,512 | 31 | 38.0% |
| Guilford, ME | 494 | 31 | 38.0% |
| City | Population | Air Quality Index | National Avg. |
| Sabula, IA | 494 | 42 | 16.0% |
| Centertown, KY | 494 | 43 | 14.0% |
| Fleming-Neon, KY | 494 | 45 | 10.0% |
| Supreme, LA | 494 | 41 | 18.0% |
| Avondale, MO | 494 | 47 | 6.0% |
| Guilford, ME | 494 | 31 | 38.0% |
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