Fort Peck, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 31.2 °F (low) to 57.4 °F (high). Annual precipitation averages 13.4 Inches. Fort Peck is located in USDA Plant Hardiness Zone 4a. 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 | 4.5 °F | 26.4 °F | 0.39 in. |
| February | 8.6 °F | 31.8 °F | 0.37 in. |
| March | 20.0 °F | 44.3 °F | 0.49 in. |
| April | 31.1 °F | 58.5 °F | 0.99 in. |
| May | 41.8 °F | 69.1 °F | 2.35 in. |
| June | 51.4 °F | 78.0 °F | 2.57 in. |
| July | 56.9 °F | 87.0 °F | 1.87 in. |
| August | 55.0 °F | 86.8 °F | 1.37 in. |
| September | 44.8 °F | 75.5 °F | 1.14 in. |
| October | 32.6 °F | 59.1 °F | 0.98 in. |
| November | 19.5 °F | 42.8 °F | 0.46 in. |
| December | 8.6 °F | 29.9 °F | 0.45 in. |
| Annual | 31.2 °F | 57.4 °F | 13.43 in. |
| 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 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |