Bridger, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.3 °C (low) to 15.7 °C (high). Annual precipitation averages 305.6 Millimeters. Bridger 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 | -10.2 °C | 2.6 °C | 10.67 mm |
| February | -9.3 °C | 4.3 °C | 9.65 mm |
| March | -4.6 °C | 10.5 °C | 16 mm |
| April | -0.4 °C | 14.6 °C | 38.35 mm |
| May | 4.7 °C | 19.8 °C | 56.64 mm |
| June | 9.1 °C | 25.1 °C | 49.02 mm |
| July | 12.3 °C | 30.9 °C | 21.34 mm |
| August | 10.9 °C | 30.1 °C | 16.76 mm |
| September | 6.2 °C | 24.1 °C | 29.21 mm |
| October | 0.1 °C | 15.7 °C | 32.26 mm |
| November | -5.3 °C | 8.2 °C | 14.22 mm |
| December | -9.9 °C | 2.6 °C | 11.43 mm |
| Annual | 0.3 °C | 15.7 °C | 305.55 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 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |