Chester, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 0.2 °C (low) to 17.1 °C (high). Annual precipitation averages 838.5 Millimeters. Chester is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.9 °C | 6.4 °C | 151.64 mm |
| February | -5.2 °C | 8.2 °C | 134.11 mm |
| March | -3.4 °C | 10.9 °C | 128.02 mm |
| April | -1.5 °C | 14.1 °C | 64.26 mm |
| May | 2.1 °C | 19.4 °C | 46.99 mm |
| June | 5.3 °C | 25.1 °C | 19.05 mm |
| July | 8.1 °C | 30.2 °C | 8.89 mm |
| August | 7.5 °C | 29.7 °C | 5.08 mm |
| September | 4.2 °C | 26.1 °C | 8.13 mm |
| October | -0.1 °C | 19.1 °C | 42.93 mm |
| November | -3.2 °C | 10.7 °C | 82.04 mm |
| December | -5.9 °C | 5.8 °C | 147.32 mm |
| Annual | 0.2 °C | 17.1 °C | 838.46 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 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 |