Lethbridge, Alberta climate data is summarized below. Average annual temperatures range from 32.5 °F (low) to 54.7 °F (high). Annual precipitation averages 13.8 Inches. Lethbridge is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -23.4 °F | -17.8 °F | 0 in. |
| February | -22.8 °F | -16.8 °F | 0 in. |
| March | -20.2 °F | -13.9 °F | 76.2 in. |
| April | -18.1 °F | -11.1 °F | 939.8 in. |
| May | -15.3 °F | -7.9 °F | 1651 in. |
| June | -12.8 °F | -5.8 °F | 2540 in. |
| July | -11.2 °F | -3.2 °F | 1244.6 in. |
| August | -12 °F | -3.4 °F | 812.8 in. |
| September | -14.2 °F | -6 °F | 863.6 in. |
| October | -17 °F | -10.1 °F | 711.2 in. |
| November | -20.5 °F | -14.7 °F | 50.8 in. |
| December | -24.1 °F | -18.5 °F | 0 in. |
| Annual | 32.5 °F | 54.7 °F | 13.79 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |