Peerless, Montana has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from -2 °C (low) to 10.8 °C (high). Annual precipitation averages 361.2 Millimeters. Peerless is located in USDA Plant Hardiness Zone 4a. 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 | -16.3 °C | -5.9 °C | 11.18 mm |
| February | -14.5 °C | -3.8 °C | 8.89 mm |
| March | -8.7 °C | 2.9 °C | 15.49 mm |
| April | -2.2 °C | 11.3 °C | 24.89 mm |
| May | 3.7 °C | 17.7 °C | 51.82 mm |
| June | 9.1 °C | 22.4 °C | 79.5 mm |
| July | 11.9 °C | 26.9 °C | 55.63 mm |
| August | 11 °C | 27.1 °C | 35.31 mm |
| September | 5.7 °C | 20.9 °C | 29.97 mm |
| October | -1 °C | 11.9 °C | 21.59 mm |
| November | -8.3 °C | 2.6 °C | 14.22 mm |
| December | -14.2 °C | -4 °C | 12.7 mm |
| Annual | -2 °C | 10.8 °C | 361.19 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |