| 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. |
| Bethlehem, NH | 1,061 | 40 | 20.0% |
| 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% |
| 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
Safest States In The US
See the best places to live in Lancaster
These are the 10 cheapest cities in New Hampshire