Corwin Springs, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 31.4 °F (low) to 57.7 °F (high). Annual precipitation averages 11.7 Inches. Corwin Springs is located in USDA Plant Hardiness Zone 5a. 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 | 15.1 °F | 33.6 °F | 0.59 in. |
| February | 15.5 °F | 37.1 °F | 0.54 in. |
| March | 23.3 °F | 46.7 °F | 0.74 in. |
| April | 30.2 °F | 55.7 °F | 0.94 in. |
| May | 37.9 °F | 65.4 °F | 1.61 in. |
| June | 44.5 °F | 75.2 °F | 1.71 in. |
| July | 50.2 °F | 85.6 °F | 1.09 in. |
| August | 48.7 °F | 84.8 °F | 0.8 in. |
| September | 41.6 °F | 74.6 °F | 0.97 in. |
| October | 32.6 °F | 58.8 °F | 1.07 in. |
| November | 22.7 °F | 42.5 °F | 0.95 in. |
| December | 15.0 °F | 32.5 °F | 0.69 in. |
| Annual | 31.4 °F | 57.7 °F | 11.7 in. |
| 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |