Neihart, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -4.4 °C (low) to 10.9 °C (high). Annual precipitation averages 685.3 Millimeters. Neihart is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around Jun. 11 - Jun. 20 through the first frost around Aug. 1 - Aug. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.1 °C | 0.2 °C | 47.24 mm |
| February | -12.9 °C | 0.8 °C | 42.67 mm |
| March | -9.4 °C | 5.2 °C | 48.26 mm |
| April | -5.6 °C | 9.2 °C | 72.9 mm |
| May | -1.1 °C | 14 °C | 87.38 mm |
| June | 2.7 °C | 18.7 °C | 98.81 mm |
| July | 5.2 °C | 24.9 °C | 50.55 mm |
| August | 4.5 °C | 24.7 °C | 46.74 mm |
| September | 1 °C | 18.8 °C | 46.48 mm |
| October | -3.7 °C | 10.8 °C | 51.05 mm |
| November | -8.6 °C | 3.7 °C | 45.97 mm |
| December | -12.8 °C | -0.6 °C | 47.24 mm |
| Annual | -4.4 °C | 10.9 °C | 685.29 mm |
| Average First Frost Date | Aug. 1 - Aug. 10 |
| Average Last Frost Date | Jun. 11 - Jun. 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |