| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 0°F | 18°F | 8°F | 5.9" |
| February | 0°F | 19°F | 9°F | 2.1" |
| March | 15°F | 33°F | 23°F | 1.9" |
| April | 30°F | 53°F | 40°F | 1.3" |
| May | 41°F | 66°F | 53°F | 3.6" |
| June | 53°F | 76°F | 64°F | 4.0" |
| July | 58°F | 80°F | 68°F | 2.5" |
| August | 55°F | 80°F | 66°F | 2.4" |
| September | 48°F | 72°F | 58°F | 2.4" |
| October | 35°F | 56°F | 44°F | 1.3" |
| November | 20°F | 38°F | 28°F | 1.1" |
| December | 3°F | 19°F | 11°F | 4.2" |
| Index | Langdon | North Dakota | National |
| Air quality index | 33 | 35 | 42 |
| Pollution index | 240,103 | 1,038,665 | 2,726,193 |
| Measurement | Total |
| Days measured | 363 |
| Days with good air quality | 327 |
| Days with moderate air quality | 34 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.004% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Milton, ND | 47 | 33 | 34.0% |
| Wales, ND | 9 | 33 | 34.0% |
| Osnabrock, ND | 134 | 33 | 34.0% |
| Alsen, ND | 21 | 33 | 34.0% |
| Loma, ND | 14 | 33 | 34.0% |
| Langdon, ND | 2,007 | 33 | 34.0% |
| City | Population | Air Quality Index | National Avg. |
| Prophetstown, IL | 2,007 | 42 | 16.0% |
| Winfield, MO | 2,007 | 54 | 8.0% |
| Kenvil, NJ | 2,007 | 34 | 32.0% |
| Gordon, GA | 2,008 | 38 | 24.0% |
| Malad City, ID | 2,008 | 44 | 12.0% |
| Langdon, ND | 2,007 | 33 | 34.0% |