Richfield, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 9.5 °C (low) to 23.9 °C (high). Annual precipitation averages 596.4 Millimeters. Richfield is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 11 - Feb. 20 through the first frost around Dec. 1 - Dec. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.3 °C | 13.5 °C | 118.62 mm |
| February | 4.5 °C | 16 °C | 100.58 mm |
| March | 5.9 °C | 18.8 °C | 83.57 mm |
| April | 7.6 °C | 21.8 °C | 37.08 mm |
| May | 11.4 °C | 26.8 °C | 31.24 mm |
| June | 15.2 °C | 31.4 °C | 10.67 mm |
| July | 17.2 °C | 35 °C | 0.76 mm |
| August | 16.2 °C | 34.2 °C | 2.29 mm |
| September | 14.1 °C | 32.2 °C | 5.59 mm |
| October | 10.2 °C | 26.1 °C | 22.86 mm |
| November | 5.6 °C | 18.2 °C | 67.82 mm |
| December | 3 °C | 13.3 °C | 115.32 mm |
| Annual | 9.5 °C | 23.9 °C | 596.4 mm |
| Average First Frost Date | Dec. 1 - Dec. 10 |
| Average Last Frost Date | Feb. 11 - Feb. 20 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |