Cromberg, California has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 1.3 °C (low) to 18.1 °C (high). Annual precipitation averages 1099.3 Millimeters. Cromberg is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.7 °C | 7.4 °C | 204.22 mm |
| February | -3.8 °C | 9.3 °C | 184.4 mm |
| March | -1.9 °C | 11.9 °C | 164.34 mm |
| April | -0.1 °C | 15.3 °C | 93.47 mm |
| May | 3.2 °C | 20.2 °C | 56.13 mm |
| June | 6.4 °C | 25.8 °C | 20.32 mm |
| July | 9.3 °C | 30.7 °C | 4.32 mm |
| August | 8.4 °C | 30.3 °C | 3.81 mm |
| September | 5.2 °C | 27.1 °C | 14.48 mm |
| October | 0.9 °C | 20.1 °C | 54.86 mm |
| November | -2.4 °C | 11.9 °C | 101.85 mm |
| December | -4.8 °C | 6.7 °C | 197.1 mm |
| Annual | 1.3 °C | 18.1 °C | 1099.3 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |