Downieville, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 39.9 °F (low) to 68.1 °F (high). Annual precipitation averages 65.2 Inches. Downieville is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 30.5 °F | 49.2 °F | 12.73 in. |
| February | 31.4 °F | 53.3 °F | 11.22 in. |
| March | 33.5 °F | 58.2 °F | 9.58 in. |
| April | 36.2 °F | 63.0 °F | 5.21 in. |
| May | 42.4 °F | 71.8 °F | 3.76 in. |
| June | 47.5 °F | 81.1 °F | 0.93 in. |
| July | 53.4 °F | 89.2 °F | 0.08 in. |
| August | 52.4 °F | 89.2 °F | 0.19 in. |
| September | 47.6 °F | 84.0 °F | 0.68 in. |
| October | 40.2 °F | 72.8 °F | 3.14 in. |
| November | 33.7 °F | 57.3 °F | 6.07 in. |
| December | 30.4 °F | 47.7 °F | 11.63 in. |
| Annual | 39.9 °F | 68.1 °F | 65.22 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |