Grano, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.7 °C (low) to 10.4 °C (high). Annual precipitation averages 454.4 Millimeters. Grano is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -18.1 °C | -8 °C | 14.99 mm |
| February | -15.8 °C | -5.3 °C | 12.95 mm |
| March | -9.5 °C | 1.3 °C | 19.05 mm |
| April | -2.1 °C | 11.2 °C | 23.37 mm |
| May | 5 °C | 18.5 °C | 65.79 mm |
| June | 11.1 °C | 23.3 °C | 91.69 mm |
| July | 13.3 °C | 26.7 °C | 67.06 mm |
| August | 11.8 °C | 26.9 °C | 49.53 mm |
| September | 6.7 °C | 21.4 °C | 38.86 mm |
| October | -0.3 °C | 12.2 °C | 34.8 mm |
| November | -8.1 °C | 2.2 °C | 19.3 mm |
| December | -14.8 °C | -5.2 °C | 17.02 mm |
| Annual | -1.7 °C | 10.4 °C | 454.41 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°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 |