Rosthern, Saskatchewan climate data is summarized below. Average annual temperatures range from -3.3 °C (low) to 7.8 °C (high). Annual precipitation averages 434 Millimeters. 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 | -19.43 °C | -9.85 °C | 0 mm |
| February | -19.65 °C | -9.21 °C | 0 mm |
| March | -11.84 °C | -1.96 °C | 0 mm |
| April | -3.16 °C | 8.16 °C | 27 mm |
| May | 3.48 °C | 17.77 °C | 52 mm |
| June | 9.54 °C | 22.07 °C | 122 mm |
| July | 12.34 °C | 24.95 °C | 99 mm |
| August | 10.64 °C | 24.38 °C | 54 mm |
| September | 5.5 °C | 19.4 °C | 42 mm |
| October | -0.06 °C | 9.78 °C | 38 mm |
| November | -9.09 °C | -1.63 °C | 0 mm |
| December | -18.06 °C | -10.48 °C | 0 mm |
| Annual | -3.3 °C | 7.8 °C | 434 mm |
| 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°C to -37.2°C |
| Current Drought Conditions | Normal |