| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | -1°F | 15°F | 7°F | 5.1" |
| February | -3°F | 14°F | 6°F | 5.8" |
| March | 6°F | 21°F | 13°F | 6.2" |
| April | 19°F | 32°F | 25°F | 7.8" |
| May | 32°F | 44°F | 37°F | 8.4" |
| June | 40°F | 51°F | 45°F | 9.7" |
| July | 45°F | 55°F | 50°F | 9.0" |
| August | 42°F | 54°F | 48°F | 8.6" |
| September | 38°F | 49°F | 44°F | 6.7" |
| October | 27°F | 38°F | 32°F | 10.4" |
| November | 16°F | 30°F | 23°F | 7.0" |
| December | 5°F | 21°F | 13°F | 8.7" |
| Index | Bartlett | New Hampshire | National |
| Air quality index | 40 | 34 | 42 |
| Pollution index | 2,712,920 | 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 | 0.030% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.050% |
| Mercury | 0.070% |
| City | Population | Air Quality Index | National Avg. |
| Conway, NH | 3,965 | 31 | 38.0% |
| North Conway, NH | 2,410 | 40 | 20.0% |
| Fryeburg, ME | 1,533 | 40 | 20.0% |
| Bartlett, NH | 184 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Deer Creek, AZ | 184 | 74 | 48.0% |
| Clio, CA | 184 | 44 | 12.0% |
| Lodoga, CA | 184 | 31 | 38.0% |
| Tooleville, CA | 184 | 60 | 20.0% |
| Farmington, DE | 184 | 36 | 28.0% |
| Bartlett, NH | 184 | 40 | 20.0% |
Here are the best places to live in New Hampshire
These are the largest cities in New Hampshire
Check out the 10 most dangerous cities in New Hampshire
Most Dangerous Cities In The US