Corwin Springs, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.3 °C (low) to 14.3 °C (high). Annual precipitation averages 297.2 Millimeters. 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 | -9.4 °C | 0.9 °C | 14.99 mm |
| February | -9.2 °C | 2.8 °C | 13.72 mm |
| March | -4.8 °C | 8.2 °C | 18.8 mm |
| April | -1 °C | 13.2 °C | 23.88 mm |
| May | 3.3 °C | 18.6 °C | 40.89 mm |
| June | 6.9 °C | 24 °C | 43.43 mm |
| July | 10.1 °C | 29.8 °C | 27.69 mm |
| August | 9.3 °C | 29.3 °C | 20.32 mm |
| September | 5.3 °C | 23.7 °C | 24.64 mm |
| October | 0.3 °C | 14.9 °C | 27.18 mm |
| November | -5.2 °C | 5.8 °C | 24.13 mm |
| December | -9.4 °C | 0.3 °C | 17.53 mm |
| Annual | -0.3 °C | 14.3 °C | 297.2 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 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |