Courtenay, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.9 °C (low) to 10.7 °C (high). Annual precipitation averages 514.1 Millimeters. Courtenay is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -17.7 °C | -7.9 °C | 11.94 mm |
| February | -15.6 °C | -5.3 °C | 11.43 mm |
| March | -8.9 °C | 1.6 °C | 18.03 mm |
| April | -1.4 °C | 11.1 °C | 27.18 mm |
| May | 5.9 °C | 18.9 °C | 72.39 mm |
| June | 12.2 °C | 24.1 °C | 92.2 mm |
| July | 14.5 °C | 26.9 °C | 95.25 mm |
| August | 12.9 °C | 26.6 °C | 61.98 mm |
| September | 7.7 °C | 21.6 °C | 54.61 mm |
| October | 0.7 °C | 12.8 °C | 40.39 mm |
| November | -7.1 °C | 2.8 °C | 15.49 mm |
| December | -13.8 °C | -4.9 °C | 13.21 mm |
| Annual | -0.9 °C | 10.7 °C | 514.1 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |