| 2023 Hardiness Zone: | Zone 10b: 35°F to 40°F |
| 2012 Hardiness Zone: | Zone 10b: 35°F to 40°F Zone 10a: 30°F to 35°F |
| 1990 Hardiness Zone: | Zone 10a: 30F to 35F |
| Average First Frost Date: | No Frost |
| Average Last Frost Date: | No Frost |
| Koppen-Geiger Climate Zone: | BSk - Cold Semi-Arid Climate |
| Ecoregion: | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 92173 - San Ysidro, CA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 45 | 47 | 49 | 52 | 56 | 59 | 63 | 64 | 63 | 57 | 49 | 45 | 54 |
| Avg Max Temp (°F) | 68 | 68 | 70 | 71 | 73 | 77 | 81 | 83 | 82 | 78 | 73 | 68 | 74 |
| Avg Precip (In.) | 2.56 | 2.33 | 2.5 | .86 | .24 | .09 | .03 | .11 | .28 | .47 | 1.22 | 1.4 | 12.09 |