| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 13°F | 30°F | 22°F | 2.4" |
| February | 15°F | 33°F | 23°F | 2.3" |
| March | 22°F | 41°F | 31°F | 2.9" |
| April | 35°F | 56°F | 44°F | 4.3" |
| May | 45°F | 67°F | 55°F | 3.7" |
| June | 54°F | 74°F | 63°F | 5.1" |
| July | 60°F | 81°F | 70°F | 3.4" |
| August | 59°F | 79°F | 68°F | 4.3" |
| September | 52°F | 72°F | 61°F | 4.2" |
| October | 42°F | 60°F | 50°F | 6.0" |
| November | 31°F | 48°F | 39°F | 4.2" |
| December | 20°F | 35°F | 27°F | 4.0" |
| Index | Winthrop | Maine | National |
| Air quality index | 28 | 33 | 42 |
| Pollution index | 3,644,290 | 3,417,521 | 2,726,193 |
| Measurement | Total |
| Days measured | 361 |
| Days with good air quality | 356 |
| Days with moderate air quality | 5 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.030% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.030% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Farmingdale, ME | 2,451 | 28 | 44.0% |
| Chisholm, ME | 1,165 | 28 | 44.0% |
| Gardiner, ME | 5,670 | 28 | 44.0% |
| Livermore Falls, ME | 1,688 | 28 | 44.0% |
| Hallowell, ME | 2,444 | 28 | 44.0% |
| Winthrop, ME | 2,476 | 28 | 44.0% |
| City | Population | Air Quality Index | National Avg. |
| New London, OH | 2,476 | 43 | 14.0% |
| Roaring Spring, PA | 2,475 | 41 | 18.0% |
| Wayne, IL | 2,477 | 55 | 10.0% |
| Spring Lake, MI | 2,477 | 38 | 24.0% |
| Nicholson, MS | 2,477 | 45 | 10.0% |
| Winthrop, ME | 2,476 | 28 | 44.0% |
Here are the best places to live in Maine
These are the largest cities in Maine
Check out the 10 most dangerous cities in Maine
Check out the 10 safest cities in Maine