Rainbow, California has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 52.3 °F (low) to 76.9 °F (high). Annual precipitation averages 16.2 Inches. Rainbow is located in USDA Plant Hardiness Zone 10a. The growing season typically runs from the last frost around Feb. 1 - Feb. 10 through the first frost around Dec. 21 - Dec. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 45.6 °F | 67.5 °F | 2.83 in. |
| February | 45.9 °F | 67.1 °F | 4.21 in. |
| March | 46.8 °F | 68.6 °F | 2.42 in. |
| April | 48.6 °F | 72.4 °F | 1.1 in. |
| May | 52.6 °F | 76.2 °F | 0.59 in. |
| June | 55.7 °F | 81.2 °F | 0.2 in. |
| July | 60.0 °F | 88.1 °F | 0.14 in. |
| August | 61.3 °F | 90.0 °F | 0.07 in. |
| September | 60.2 °F | 88.6 °F | 0.13 in. |
| October | 55.8 °F | 82.8 °F | 0.64 in. |
| November | 50.0 °F | 73.7 °F | 1.13 in. |
| December | 45.0 °F | 66.8 °F | 2.77 in. |
| Annual | 52.3 °F | 76.9 °F | 16.23 in. |
| Average First Frost Date | Dec. 21 - Dec. 31 |
| Average Last Frost Date | Feb. 1 - Feb. 10 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 10a : 30°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 10a : 30°F to 25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |