Cardwell, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.9 °C (low) to 15.2 °C (high). Annual precipitation averages 334 Millimeters. Cardwell 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.1 - Sep. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.7 °C | 2.3 °C | 13.72 mm |
| February | -8.7 °C | 4.6 °C | 9.65 mm |
| March | -5.2 °C | 9.4 °C | 21.08 mm |
| April | -1.6 °C | 14.4 °C | 39.12 mm |
| May | 3.2 °C | 19.1 °C | 55.63 mm |
| June | 6.8 °C | 23.9 °C | 59.44 mm |
| July | 9.5 °C | 30.3 °C | 28.45 mm |
| August | 8.2 °C | 29.5 °C | 21.84 mm |
| September | 4.1 °C | 23.4 °C | 30.23 mm |
| October | -1.1 °C | 16 °C | 26.42 mm |
| November | -5.9 °C | 7.3 °C | 16 mm |
| December | -9.8 °C | 2.1 °C | 12.45 mm |
| Annual | -0.9 °C | 15.2 °C | 334.03 mm |
| Average First Frost Date | Sep.1 - Sep. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 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 | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |