Cardwell, Montana has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 30.5 °F (low) to 59.3 °F (high). Annual precipitation averages 13.2 Inches. 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 | 14.5 °F | 36.2 °F | 0.54 in. |
| February | 16.4 °F | 40.2 °F | 0.38 in. |
| March | 22.7 °F | 49.0 °F | 0.83 in. |
| April | 29.2 °F | 57.9 °F | 1.54 in. |
| May | 37.7 °F | 66.4 °F | 2.19 in. |
| June | 44.2 °F | 75.0 °F | 2.34 in. |
| July | 49.1 °F | 86.5 °F | 1.12 in. |
| August | 46.8 °F | 85.1 °F | 0.86 in. |
| September | 39.4 °F | 74.1 °F | 1.19 in. |
| October | 30.0 °F | 60.8 °F | 1.04 in. |
| November | 21.3 °F | 45.2 °F | 0.63 in. |
| December | 14.4 °F | 35.7 °F | 0.49 in. |
| Annual | 30.5 °F | 59.3 °F | 13.15 in. |
| 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 : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |