Sun Prairie, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.7 °C (low) to 14.7 °C (high). Annual precipitation averages 350.3 Millimeters. Sun Prairie is located in USDA Plant Hardiness Zone 4b. 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 | -8.9 °C | 2.5 °C | 12.45 mm |
| February | -8.7 °C | 3.7 °C | 12.19 mm |
| March | -5.1 °C | 8.3 °C | 14.99 mm |
| April | -0.4 °C | 13.3 °C | 39.88 mm |
| May | 4.4 °C | 18.6 °C | 55.37 mm |
| June | 8.7 °C | 23.2 °C | 70.36 mm |
| July | 11.6 °C | 29.4 °C | 29.97 mm |
| August | 10.8 °C | 28.9 °C | 30.73 mm |
| September | 6.4 °C | 22.8 °C | 31.75 mm |
| October | 1.3 °C | 14.8 °C | 24.89 mm |
| November | -3.7 °C | 7.7 °C | 15.49 mm |
| December | -7.9 °C | 2.8 °C | 12.19 mm |
| Annual | 0.7 °C | 14.7 °C | 350.26 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |