| 2023 Hardiness Zone: | Zone 10b: 35°F to 40°F Zone 8b: 15°F to 20°F Zone 10a: 30°F to 35°F Zone 9b: 25°F to 30°F Zone 9a: 20°F to 25°F | |
| 2012 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 9a: 20°F to 25°F Zone 10a: 30°F to 35°F Zone 9b: 25°F to 30°F | |
| 1990 Hardiness Zone: | Zone 10a: 30F to 35F | |
| Average First Frost Date: | Jan. 1 - Jan. 10 | |
| Average Last Frost Date: | Feb. 21 - Feb. 29 | |
| Koppen-Geiger Climate Zone: | Csa - Hot-Summer Mediterranean Climate | |
| Ecoregion: | ||
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 91001 - Altadena, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 41 | 42 | 43 | 47 | 51 | 56 | 61 | 62 | 60 | 53 | 46 | 41 | 50 |
| Avg Max Temp (°F) | 59 | 62 | 65 | 70 | 75 | 82 | 89 | 89 | 84 | 75 | 67 | 60 | 73 |
| Avg Precip (In.) | 5.46 | 6.29 | 5.73 | 1.6 | .71 | .21 | .05 | .21 | .61 | .89 | 1.89 | 3.11 | 26.76 |