Average annual temperature is 19.2 °C
Absolute maximum temperature: 42.4 °C
Absolute minimum temperature: -4.0 °C
Number of sunny days: 303 days
Number of rainy days: 61 days
Number of snow days: 1 day
Look at detailed online map of San Ysidro
* Weather data for San Ysidro United States is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 18.5 | 21.9 | 25.4 | 32.6 | 34.5 | 41.3 | 42.1 | 42.4 | 38.8 | 32.1 | 28.5 | 21.1 |
| Average daytime temperature (°C) | 13.8 | 15.6 | 20.7 | 26.4 | 30.8 | 35.4 | 39.5 | 36.0 | 34.2 | 27.8 | 19.6 | 15.2 |
| Average temperature (°C) | 7.2 | 8.0 | 13.5 | 18.7 | 23.9 | 28.6 | 32.9 | 29.1 | 27.0 | 20.4 | 12.6 | 8.2 |
| Average night temperature (°C) | 1.6 | 2.2 | 6.5 | 10.4 | 15.6 | 20.2 | 24.6 | 21.9 | 18.7 | 12.6 | 5.8 | 1.7 |
| Absolute minimum temperature (°C) | -3.2 | -4.0 | -2.2 | -0.3 | 10.6 | 13.9 | 20.3 | 17.3 | 14.6 | -0.7 | 1.1 | -3.2 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 14.0 | 13.0 | 12.0 | 11.0 | 10.0 | 10.0 |
| Daylight mean duration (h) | 10.3 | 11.0 | 12.0 | 13.0 | 13.8 | 14.2 | 14.0 | 13.3 | 12.4 | 11.4 | 10.5 | 10.1 |
| Daylight minimum duration (h) | 10.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 13.0 | 12.0 | 11.0 | 10.0 | 10.0 | 10.0 |
| Sunshine mean duration (h) | 8.6 | 8.8 | 10.2 | 12.0 | 12.3 | 12.7 | 12.8 | 11.6 | 11.3 | 10.1 | 8.9 | 8.4 |
| Precipitation (mm) | 8 | 12 | 10 | 0 | 11 | 1 | 1 | 15 | 5 | 1 | 27 | 32 |
| Sunny days | 25 | 18 | 24 | 30 | 24 | 27 | 30 | 23 | 24 | 29 | 23 | 26 |
| Rainy days | 6 | 10 | 6 | 0 | 7 | 3 | 1 | 8 | 6 | 2 | 7 | 5 |
| Snow days | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The largest precipitation sum in San Ysidro is at