Rugby, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -2.3 °C (low) to 9.8 °C (high). Annual precipitation averages 485.4 Millimeters. Rugby is located in USDA Plant Hardiness Zone 3b. 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 | -19.6 °C | -9.1 °C | 12.45 mm |
| February | -17.7 °C | -6.6 °C | 13.21 mm |
| March | -10.3 °C | 0.3 °C | 18.29 mm |
| April | -2.3 °C | 10.6 °C | 25.65 mm |
| May | 4.9 °C | 18.3 °C | 66.8 mm |
| June | 11.2 °C | 23.2 °C | 94.74 mm |
| July | 13.4 °C | 26.2 °C | 84.33 mm |
| August | 11.8 °C | 26.2 °C | 56.39 mm |
| September | 6.6 °C | 20.9 °C | 43.69 mm |
| October | -0.7 °C | 11.8 °C | 36.58 mm |
| November | -8.7 °C | 1.6 °C | 17.27 mm |
| December | -15.9 °C | -6.3 °C | 16 mm |
| Annual | -2.3 °C | 9.8 °C | 485.4 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 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 |