Belt, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 0.3 °C (low) to 14.5 °C (high). Annual precipitation averages 432.8 Millimeters. Belt 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 | -9.7 °C | 2.3 °C | 17.53 mm |
| February | -9.1 °C | 3.4 °C | 14.99 mm |
| March | -5.4 °C | 8.2 °C | 19.3 mm |
| April | -0.7 °C | 13.3 °C | 46.23 mm |
| May | 4.1 °C | 18.5 °C | 65.53 mm |
| June | 8.4 °C | 23.1 °C | 86.36 mm |
| July | 11.3 °C | 29.2 °C | 35.56 mm |
| August | 10.5 °C | 28.8 °C | 34.04 mm |
| September | 6.2 °C | 22.8 °C | 41.66 mm |
| October | 1.1 °C | 14.8 °C | 33.53 mm |
| November | -4.5 °C | 7.4 °C | 20.57 mm |
| December | -8.8 °C | 2.7 °C | 17.53 mm |
| Annual | 0.3 °C | 14.5 °C | 432.83 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 |