Arthur, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.6 °C (low) to 11.1 °C (high). Annual precipitation averages 592.1 Millimeters. Arthur 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 | -18.5 °C | -8.6 °C | 13.46 mm |
| February | -16.1 °C | -5.5 °C | 13.46 mm |
| March | -8.6 °C | 1.4 °C | 23.88 mm |
| April | -0.6 °C | 11.9 °C | 32 mm |
| May | 6.7 °C | 20.1 °C | 78.49 mm |
| June | 12.9 °C | 25.1 °C | 102.36 mm |
| July | 14.9 °C | 27.3 °C | 93.47 mm |
| August | 13.3 °C | 26.9 °C | 68.83 mm |
| September | 8.3 °C | 22.3 °C | 72.14 mm |
| October | 1.4 °C | 13.4 °C | 55.63 mm |
| November | -6.6 °C | 3.3 °C | 19.05 mm |
| December | -13.9 °C | -4.9 °C | 19.3 mm |
| Annual | -0.6 °C | 11.1 °C | 592.07 mm |
| 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 : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |