Stevensville, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.1 °C (low) to 15.4 °C (high). Annual precipitation averages 312.9 Millimeters. Stevensville is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.6 °C | 2.1 °C | 23.37 mm |
| February | -6.4 °C | 4.9 °C | 21.08 mm |
| March | -3.5 °C | 10.3 °C | 20.07 mm |
| April | -0.6 °C | 15 °C | 23.37 mm |
| May | 3.2 °C | 20.2 °C | 37.59 mm |
| June | 6.9 °C | 24.3 °C | 41.4 mm |
| July | 9.3 °C | 30.8 °C | 18.8 mm |
| August | 8.3 °C | 30 °C | 20.57 mm |
| September | 4.4 °C | 24 °C | 21.59 mm |
| October | -0.3 °C | 15.3 °C | 26.67 mm |
| November | -4.5 °C | 6.4 °C | 29.21 mm |
| December | -7.6 °C | 1.2 °C | 29.21 mm |
| Annual | 0.1 °C | 15.4 °C | 312.93 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |