Buchanan, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.8 °C (low) to 10.9 °C (high). Annual precipitation averages 516.6 Millimeters. Buchanan is located in USDA Plant Hardiness Zone 4b. 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 | -17.4 °C | -7.6 °C | 11.94 mm |
| February | -15.3 °C | -5 °C | 11.68 mm |
| March | -8.8 °C | 1.9 °C | 19.05 mm |
| April | -1.3 °C | 11.3 °C | 27.18 mm |
| May | 5.9 °C | 18.9 °C | 74.17 mm |
| June | 12.2 °C | 24.2 °C | 89.41 mm |
| July | 14.6 °C | 27.1 °C | 93.22 mm |
| August | 12.9 °C | 26.7 °C | 59.69 mm |
| September | 7.8 °C | 21.7 °C | 56.13 mm |
| October | 0.7 °C | 12.9 °C | 42.42 mm |
| November | -7.1 °C | 3.1 °C | 15.75 mm |
| December | -13.7 °C | -4.6 °C | 16 mm |
| Annual | -0.8 °C | 10.9 °C | 516.64 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 4b : -31.7°C to -28.9°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 |