San Bernardino, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 11.3 °C (low) to 26.5 °C (high). Annual precipitation averages 309.1 Millimeters. San Bernardino is located in USDA Plant Hardiness Zone 10a. The growing season typically runs from the last frost around Feb. 11 - Feb. 20 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.1 °C | 19.6 °C | 67.56 mm |
| February | 6.7 °C | 19.7 °C | 75.18 mm |
| March | 8.2 °C | 21.7 °C | 50.55 mm |
| April | 9.7 °C | 24.2 °C | 18.8 mm |
| May | 12.3 °C | 26.9 °C | 7.87 mm |
| June | 14.6 °C | 31.1 °C | 2.03 mm |
| July | 17.4 °C | 34.9 °C | 1.52 mm |
| August | 17.9 °C | 35.6 °C | 1.52 mm |
| September | 16.4 °C | 33.6 °C | 3.81 mm |
| October | 12.6 °C | 28.3 °C | 13.21 mm |
| November | 8.5 °C | 23.4 °C | 19.05 mm |
| December | 5.6 °C | 19.1 °C | 48.01 mm |
| Annual | 11.3 °C | 26.5 °C | 309.11 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 11 - Feb. 20 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 10a : -1.1°C to 1.7°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |