Angwin, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 9 °C (low) to 20.9 °C (high). Annual precipitation averages 1067.3 Millimeters. Angwin is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Dec. 1 - Dec. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.9 °C | 12.8 °C | 217.93 mm |
| February | 5.3 °C | 14.1 °C | 206.5 mm |
| March | 5.7 °C | 16.2 °C | 144.27 mm |
| April | 6.8 °C | 18.6 °C | 68.83 mm |
| May | 9.2 °C | 22.4 °C | 40.64 mm |
| June | 11.9 °C | 26.7 °C | 10.16 mm |
| July | 14 °C | 29.7 °C | 0.25 mm |
| August | 13.8 °C | 29.7 °C | 1.27 mm |
| September | 13.6 °C | 28.2 °C | 4.32 mm |
| October | 11.2 °C | 23.4 °C | 51.05 mm |
| November | 7.2 °C | 16.5 °C | 100.33 mm |
| December | 4.7 °C | 12.2 °C | 221.74 mm |
| Annual | 9 °C | 20.9 °C | 1067.29 mm |
| Average First Frost Date | Dec. 1 - Dec. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |