Harvey, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.1 °F (low) to 50.8 °F (high). Annual precipitation averages 18.2 Inches. Harvey 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 | -0.8 °F | 17.7 °F | 0.35 in. |
| February | 2.1 °F | 21.6 °F | 0.36 in. |
| March | 15.0 °F | 34.4 °F | 0.62 in. |
| April | 28.5 °F | 51.8 °F | 1.05 in. |
| May | 41.5 °F | 65.7 °F | 2.63 in. |
| June | 52.6 °F | 74.1 °F | 3.53 in. |
| July | 56.9 °F | 80.0 °F | 3.0 in. |
| August | 53.8 °F | 79.8 °F | 2.2 in. |
| September | 44.7 °F | 70.7 °F | 1.9 in. |
| October | 32.0 °F | 54.8 °F | 1.45 in. |
| November | 17.7 °F | 36.7 °F | 0.57 in. |
| December | 5.2 °F | 22.5 °F | 0.5 in. |
| Annual | 29.1 °F | 50.8 °F | 18.16 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |