Fall River Mills, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 1.6 °C (low) to 18.9 °C (high). Annual precipitation averages 484.6 Millimeters. Fall River Mills is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.2 °C | 7.8 °C | 68.33 mm |
| February | -3.2 °C | 10.1 °C | 72.14 mm |
| March | -1.4 °C | 13.1 °C | 62.99 mm |
| April | 0.5 °C | 16.4 °C | 46.48 mm |
| May | 4 °C | 21.6 °C | 37.85 mm |
| June | 7.2 °C | 26.8 °C | 19.3 mm |
| July | 9.7 °C | 31.9 °C | 2.79 mm |
| August | 8.2 °C | 31.4 °C | 4.57 mm |
| September | 4.9 °C | 28.1 °C | 8.64 mm |
| October | 0.6 °C | 20.8 °C | 28.96 mm |
| November | -2.5 °C | 12.1 °C | 53.85 mm |
| December | -4.5 °C | 6.9 °C | 78.74 mm |
| Annual | 1.6 °C | 18.9 °C | 484.64 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |