Pasadena, California has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 11.9 °C (low) to 25.3 °C (high). Annual precipitation averages 512.3 Millimeters. Pasadena is located in USDA Plant Hardiness Zone 10b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.9 °C | 20.2 °C | 120.4 mm |
| February | 8 °C | 20.3 °C | 123.7 mm |
| March | 9.1 °C | 21.6 °C | 84.84 mm |
| April | 10.3 °C | 23.4 °C | 28.45 mm |
| May | 12.3 °C | 24.8 °C | 13.21 mm |
| June | 14.3 °C | 27.6 °C | 5.08 mm |
| July | 16.6 °C | 30.7 °C | 1.52 mm |
| August | 17.1 °C | 32.5 °C | 0.51 mm |
| September | 16.2 °C | 31 °C | 5.59 mm |
| October | 13.7 °C | 27.7 °C | 20.07 mm |
| November | 9.9 °C | 23.7 °C | 25.65 mm |
| December | 7.4 °C | 19.7 °C | 83.31 mm |
| Annual | 11.9 °C | 25.3 °C | 512.33 mm |
| Average First Frost Date | No Frost |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 10b : 1.7°C to 4.4°C |
| Plant Hardiness Zone - 2012 | Zone 10a : -1.1°C to 1.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |