Rocklin, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 9.6 °C (low) to 23.8 °C (high). Annual precipitation averages 646.4 Millimeters. 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 | 3.9 °C | 13.2 °C | 127.25 mm |
| February | 5 °C | 15.9 °C | 119.38 mm |
| March | 6.7 °C | 18.6 °C | 94.74 mm |
| April | 8 °C | 21.9 °C | 49.78 mm |
| May | 11.1 °C | 26.6 °C | 31.24 mm |
| June | 14.2 °C | 31.3 °C | 6.35 mm |
| July | 16.4 °C | 34.8 °C | 0.51 mm |
| August | 15.9 °C | 34.5 °C | 1.02 mm |
| September | 14 °C | 31.7 °C | 4.57 mm |
| October | 10.2 °C | 25.8 °C | 30.99 mm |
| November | 6.1 °C | 18.1 °C | 64.01 mm |
| December | 3.6 °C | 13.3 °C | 116.59 mm |
| Annual | 9.6 °C | 23.8 °C | 646.43 mm |
| 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 : -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 | Csa - Hot-Summer Mediterranean Climate |