| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 4°F | 26°F | 16°F | 2.1" |
| February | 6°F | 28°F | 17°F | 2.0" |
| March | 15°F | 37°F | 26°F | 2.8" |
| April | 29°F | 52°F | 40°F | 3.3" |
| May | 40°F | 65°F | 52°F | 4.1" |
| June | 49°F | 73°F | 61°F | 5.2" |
| July | 55°F | 79°F | 67°F | 4.3" |
| August | 53°F | 77°F | 65°F | 4.1" |
| September | 46°F | 70°F | 58°F | 3.6" |
| October | 36°F | 57°F | 46°F | 5.2" |
| November | 26°F | 44°F | 35°F | 3.9" |
| December | 13°F | 31°F | 22°F | 4.0" |
| Index | Houlton | Maine | National |
| Air quality index | 31 | 33 | 42 |
| Pollution index | 3,228,440 | 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 | 0.020% |
| Benzene | 0.040% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.040% |
| Mercury | 0.030% |
| City | Population | Air Quality Index | National Avg. |
| Houlton, ME | 5,030 | 31 | 38.0% |
| City | Population | Air Quality Index | National Avg. |
| Tara Hills, CA | 5,031 | 40 | 20.0% |
| Doney Park, AZ | 5,028 | 45 | 10.0% |
| Manheim, PA | 5,028 | 45 | 10.0% |
| Osage Beach, MO | 5,033 | 39 | 22.0% |
| Cherokee Village, AR | 5,026 | 36 | 28.0% |
| Houlton, ME | 5,030 | 31 | 38.0% |