| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 7°F | 28°F | 17°F | 1.4" |
| February | 8°F | 29°F | 18°F | 1.6" |
| March | 17°F | 39°F | 28°F | 2.0" |
| April | 31°F | 54°F | 42°F | 2.9" |
| May | 42°F | 67°F | 54°F | 4.2" |
| June | 51°F | 73°F | 62°F | 5.1" |
| July | 55°F | 78°F | 67°F | 5.3" |
| August | 53°F | 76°F | 64°F | 4.7" |
| September | 46°F | 70°F | 57°F | 3.2" |
| October | 37°F | 57°F | 46°F | 4.3" |
| November | 26°F | 45°F | 34°F | 2.4" |
| December | 16°F | 32°F | 24°F | 3.0" |
| Index | Lancaster | 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. |
| Groveton, NH | 914 | 40 | 20.0% |
| Littleton, NH | 4,294 | 40 | 20.0% |
| Concord, VT | 176 | 40 | 20.0% |
| Whitefield, NH | 1,202 | 40 | 20.0% |
| Bethlehem, NH | 1,061 | 40 | 20.0% |
| Lancaster, NH | 1,892 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Mayville, ND | 1,892 | 33 | 34.0% |
| Summitview, WA | 1,892 | 38 | 24.0% |
| Charlotte Park, FL | 1,893 | 36 | 28.0% |
| St. Francisville, LA | 1,891 | 45 | 10.0% |
| Wellston, MO | 1,891 | 54 | 8.0% |
| Lancaster, NH | 1,892 | 40 | 20.0% |
Here are the best places to live in New Hampshire
Most Dangerous States In The US
See the best places to live in Lancaster
Check out the 10 most dangerous cities in New Hampshire