Dunsmuir, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 4.9 °C (low) to 20.4 °C (high). Annual precipitation averages 1530.4 Millimeters. Dunsmuir is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -0.8 °C | 9.6 °C | 266.95 mm |
| February | -0.4 °C | 11.6 °C | 252.22 mm |
| March | 1.2 °C | 14.6 °C | 221.49 mm |
| April | 3 °C | 17.6 °C | 113.28 mm |
| May | 6.4 °C | 23.1 °C | 79.76 mm |
| June | 9.8 °C | 27.9 °C | 28.96 mm |
| July | 13.1 °C | 33.1 °C | 6.86 mm |
| August | 11.8 °C | 32.7 °C | 4.83 mm |
| September | 8.9 °C | 29.5 °C | 16 mm |
| October | 4.7 °C | 22.1 °C | 81.28 mm |
| November | 1.3 °C | 13.8 °C | 171.96 mm |
| December | -0.8 °C | 8.8 °C | 286.77 mm |
| Annual | 4.9 °C | 20.4 °C | 1530.36 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |