| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 8°F | 28°F | 18°F | 0.2" |
| February | 9°F | 32°F | 20°F | 0.2" |
| March | 20°F | 47°F | 31°F | 0.4" |
| April | 28°F | 56°F | 41°F | 1.3" |
| May | 38°F | 68°F | 53°F | 3.3" |
| June | 49°F | 78°F | 63°F | 2.9" |
| July | 55°F | 87°F | 70°F | 2.2" |
| August | 53°F | 85°F | 68°F | 2.0" |
| September | 44°F | 76°F | 59°F | 1.9" |
| October | 33°F | 60°F | 45°F | 1.2" |
| November | 19°F | 44°F | 30°F | 0.2" |
| December | 8°F | 29°F | 18°F | 0.2" |
| Index | South Heart | North Dakota | National |
| Air quality index | 33 | 35 | 42 |
| Pollution index | 212,213 | 1,038,665 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 354 |
| Days with moderate air quality | 11 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.003% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Dickinson, ND | 23,614 | 33 | 34.0% |
| Belfield, ND | 760 | 33 | 34.0% |
| South Heart, ND | 459 | 33 | 34.0% |
| City | Population | Air Quality Index | National Avg. |
| Pleasant Valley, AK | 459 | 38 | 24.0% |
| Houston, DE | 459 | 42 | 16.0% |
| Farragut, IA | 459 | 40 | 20.0% |
| Middletown, IA | 459 | 29 | 42.0% |
| Laketon, IN | 459 | 37 | 26.0% |
| South Heart, ND | 459 | 33 | 34.0% |