Killdeer, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1 °C (low) to 12.3 °C (high). Annual precipitation averages 421.9 Millimeters. Killdeer is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15.6 °C | -4.4 °C | 10.41 mm |
| February | -13.5 °C | -1.8 °C | 8.38 mm |
| March | -7.9 °C | 4.5 °C | 16 mm |
| April | -1.8 °C | 12.3 °C | 25.91 mm |
| May | 4.7 °C | 18.8 °C | 68.07 mm |
| June | 10.2 °C | 23.9 °C | 80.26 mm |
| July | 13.1 °C | 28.2 °C | 65.28 mm |
| August | 12.1 °C | 28.2 °C | 44.96 mm |
| September | 6.7 °C | 22.7 °C | 44.45 mm |
| October | -0.2 °C | 13.4 °C | 31.75 mm |
| November | -7.3 °C | 4.4 °C | 15.24 mm |
| December | -13 °C | -2.3 °C | 11.18 mm |
| Annual | -1 °C | 12.3 °C | 421.89 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |