Pendroy, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -1 °C (low) to 12.3 °C (high). Annual precipitation averages 400.1 Millimeters. Pendroy is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.2 °C | 1.2 °C | 13.21 mm |
| February | -9.9 °C | 1.9 °C | 15.75 mm |
| March | -6.4 °C | 5.9 °C | 20.32 mm |
| April | -2.2 °C | 10.9 °C | 43.43 mm |
| May | 2.4 °C | 16.1 °C | 66.04 mm |
| June | 6.4 °C | 20.2 °C | 79.25 mm |
| July | 9.4 °C | 26.2 °C | 31.5 mm |
| August | 8.7 °C | 25.8 °C | 33.78 mm |
| September | 4.6 °C | 20.2 °C | 40.64 mm |
| October | -0.6 °C | 12.8 °C | 25.91 mm |
| November | -5.3 °C | 5.6 °C | 17.78 mm |
| December | -9.4 °C | 1.3 °C | 12.45 mm |
| Annual | -1 °C | 12.3 °C | 400.06 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |