Ravalli, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2 °C (low) to 14.8 °C (high). Annual precipitation averages 408.7 Millimeters. Ravalli is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.4 °C | 1.9 °C | 30.23 mm |
| February | -5.3 °C | 3.9 °C | 23.62 mm |
| March | -2.2 °C | 9.6 °C | 24.64 mm |
| April | 1.1 °C | 14.2 °C | 39.12 mm |
| May | 4.9 °C | 19.6 °C | 51.82 mm |
| June | 8.6 °C | 23.3 °C | 63.5 mm |
| July | 11.4 °C | 29.7 °C | 25.65 mm |
| August | 10.8 °C | 29.5 °C | 23.11 mm |
| September | 6.7 °C | 23.2 °C | 29.21 mm |
| October | 1.7 °C | 14.4 °C | 34.29 mm |
| November | -2.4 °C | 6.1 °C | 32.51 mm |
| December | -5.6 °C | 1.6 °C | 30.99 mm |
| Annual | 2 °C | 14.8 °C | 408.69 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |