Hyampom, California has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.5 °C (low) to 22.4 °C (high). Annual precipitation averages 1096.5 Millimeters. Hyampom is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.1 °C | 10.3 °C | 209.04 mm |
| February | 1.4 °C | 13.3 °C | 156.46 mm |
| March | 2.3 °C | 16.4 °C | 149.35 mm |
| April | 3.7 °C | 20.7 °C | 71.37 mm |
| May | 6.6 °C | 25.8 °C | 37.34 mm |
| June | 9.2 °C | 30.4 °C | 10.41 mm |
| July | 12.3 °C | 36.1 °C | 4.57 mm |
| August | 11.7 °C | 36 °C | 1.78 mm |
| September | 8.7 °C | 32.3 °C | 12.19 mm |
| October | 5.1 °C | 24.1 °C | 58.67 mm |
| November | 2.9 °C | 14.6 °C | 137.67 mm |
| December | 1 °C | 9.2 °C | 247.65 mm |
| Annual | 5.5 °C | 22.4 °C | 1096.5 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |