Alderpoint, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.7 °C (low) to 21.8 °C (high). Annual precipitation averages 1296.4 Millimeters. Alderpoint is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.4 °C | 12.7 °C | 266.45 mm |
| February | 3.7 °C | 14.4 °C | 197.87 mm |
| March | 4.3 °C | 16.3 °C | 175.01 mm |
| April | 5.2 °C | 20 °C | 94.49 mm |
| May | 7.5 °C | 23.5 °C | 50.55 mm |
| June | 9.6 °C | 27.7 °C | 14.73 mm |
| July | 11.4 °C | 32.2 °C | 1.52 mm |
| August | 11.2 °C | 32.1 °C | 3.56 mm |
| September | 9.1 °C | 30.9 °C | 9.4 mm |
| October | 6.7 °C | 24.4 °C | 69.85 mm |
| November | 4.9 °C | 15.8 °C | 140.72 mm |
| December | 3.1 °C | 11.8 °C | 272.29 mm |
| Annual | 6.7 °C | 21.8 °C | 1296.44 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| 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 | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |