| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 5°F | 32°F | 17°F | 0.2" |
| February | 10°F | 34°F | 21°F | 0.6" |
| March | 23°F | 51°F | 35°F | 1.7" |
| April | 29°F | 58°F | 43°F | 1.8" |
| May | 40°F | 67°F | 53°F | 5.9" |
| June | 52°F | 78°F | 64°F | 5.0" |
| July | 57°F | 91°F | 74°F | 3.8" |
| August | 52°F | 85°F | 68°F | 3.4" |
| September | 43°F | 77°F | 59°F | 1.9" |
| October | 32°F | 61°F | 45°F | 0.6" |
| November | 20°F | 46°F | 32°F | 0.9" |
| December | 8°F | 31°F | 19°F | 0.8" |
| Index | Heil | North Dakota | National |
| Air quality index | 36 | 35 | 42 |
| Pollution index | 2,791,680 | 1,038,665 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 320 |
| Days with moderate air quality | 45 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.120% |
| Benzene | 0.003% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.030% |
| Mercury | 0.050% |
| City | Population | Air Quality Index | National Avg. |
| Elgin, ND | 662 | 33 | 34.0% |
| New Leipzig, ND | 172 | 33 | 34.0% |
| Leith, ND | 53 | 36 | 28.0% |
| Carson, ND | 245 | 36 | 28.0% |
| Heil, ND | 9 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Covenant Life, AK | 9 | 20 | 60.0% |
| Stevens Village, AK | 9 | 38 | 24.0% |
| Wiseman, AK | 9 | 38 | 24.0% |
| Berkley, IA | 9 | 37 | 26.0% |
| River Bend, MO | 9 | 47 | 6.0% |
| Heil, ND | 9 | 36 | 28.0% |
Here are the best places to live in North Dakota
Most Dangerous Cities In The US
Check out the 10 most dangerous cities in North Dakota
Most Dangerous States In The US