Rosthern, Saskatchewan climate data is summarized below. Average annual temperatures range from 26 °F (low) to 46 °F (high). Annual precipitation averages 17.1 Inches. Rosthern is located in USDA Plant Hardiness Zone 3a. 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 | -28.6 °F | -23.3 °F | 0 in. |
| February | -28.7 °F | -22.9 °F | 0 in. |
| March | -24.4 °F | -18.9 °F | 0 in. |
| April | -19.5 °F | -13.2 °F | 685.8 in. |
| May | -15.8 °F | -7.9 °F | 1320.8 in. |
| June | -12.5 °F | -5.5 °F | 3098.8 in. |
| July | -10.9 °F | -3.9 °F | 2514.6 in. |
| August | -11.9 °F | -4.2 °F | 1371.6 in. |
| September | -14.7 °F | -7 °F | 1066.8 in. |
| October | -17.8 °F | -12.3 °F | 965.2 in. |
| November | -22.8 °F | -18.7 °F | 0 in. |
| December | -27.8 °F | -23.6 °F | 0 in. |
| Annual | 26 °F | 46 °F | 17.09 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 3a : -40°F to -35°F |
| Current Drought Conditions | Normal |