Langdon, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -2.9 °C (low) to 8.5 °C (high). Annual precipitation averages 518.2 Millimeters. Langdon is located in USDA Plant Hardiness Zone 3b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -20.5 °C | -10.7 °C | 11.94 mm |
| February | -19 °C | -8.2 °C | 11.43 mm |
| March | -11.4 °C | -1.3 °C | 16 mm |
| April | -2.6 °C | 8.8 °C | 24.13 mm |
| May | 4.4 °C | 17.2 °C | 76.2 mm |
| June | 10.7 °C | 22.3 °C | 99.06 mm |
| July | 12.7 °C | 24.9 °C | 89.66 mm |
| August | 11.3 °C | 24.9 °C | 66.29 mm |
| September | 6.3 °C | 19.9 °C | 52.32 mm |
| October | -0.9 °C | 10.8 °C | 36.58 mm |
| November | -9.1 °C | 0.4 °C | 18.54 mm |
| December | -16.6 °C | -7.6 °C | 16 mm |
| Annual | -2.9 °C | 8.5 °C | 518.15 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 3b : -37.2°C to -34.4°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |