Rocklin, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 49.3 °F (low) to 74.9 °F (high). Annual precipitation averages 25.5 Inches. Rocklin is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 39.0 °F | 55.8 °F | 5.01 in. |
| February | 41.0 °F | 60.6 °F | 4.7 in. |
| March | 44.0 °F | 65.5 °F | 3.73 in. |
| April | 46.4 °F | 71.5 °F | 1.96 in. |
| May | 52.0 °F | 79.8 °F | 1.23 in. |
| June | 57.6 °F | 88.3 °F | 0.25 in. |
| July | 61.5 °F | 94.7 °F | 0.02 in. |
| August | 60.6 °F | 94.1 °F | 0.04 in. |
| September | 57.2 °F | 89.0 °F | 0.18 in. |
| October | 50.4 °F | 78.5 °F | 1.22 in. |
| November | 42.9 °F | 64.6 °F | 2.52 in. |
| December | 38.5 °F | 56.0 °F | 4.59 in. |
| Annual | 49.3 °F | 74.9 °F | 25.45 in. |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |