| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 2°F | 26°F | 14°F | 2.7" |
| February | 1°F | 29°F | 15°F | 4.0" |
| March | 11°F | 37°F | 25°F | 2.5" |
| April | 27°F | 52°F | 39°F | 7.0" |
| May | 36°F | 63°F | 50°F | 4.6" |
| June | 50°F | 77°F | 63°F | 7.4" |
| July | 51°F | 79°F | 65°F | 4.8" |
| August | 50°F | 79°F | 64°F | 4.1" |
| September | 44°F | 73°F | 57°F | 3.9" |
| October | 37°F | 61°F | 47°F | 9.3" |
| November | 22°F | 44°F | 33°F | 4.9" |
| December | 10°F | 29°F | 20°F | 2.2" |
| Index | Groveton | New Hampshire | National |
| Air quality index | 40 | 34 | 42 |
| Pollution index | 1,278,430 | 3,959,618 | 2,726,193 |
| Measurement | Total |
| Days measured | 324 |
| Days with good air quality | 314 |
| Days with moderate air quality | 10 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Lancaster, NH | 1,892 | 40 | 20.0% |
| Groveton, NH | 914 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Sterrett, AL | 914 | 53 | 6.0% |
| Vandiver, AL | 914 | 53 | 6.0% |
| Browerville, MN | 914 | 29 | 42.0% |
| Camden, NC | 914 | 40 | 20.0% |
| Spiritwood, SK | 914 | n/a | |
| Groveton, NH | 914 | 40 | 20.0% |
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