Typical September weather
San Diego
California · September
77° days
66° nights
rain is rare · 12½ hours of daylight · ocean 67°
What to pack
- Sunscreen
What September feels like
September is the month San Diegans quietly hope you don't book: schools are back, the gray mornings are done, and the ocean has not started cooling. It is also when an inland heat spell can push the entire county toward the coast at once.
Rain is genuinely rare — most years, September stays dry start to finish. There’s a little humidity in the air, but nothing that changes your plans.
Can you swim?
The ocean runs about 67° — brisk but swimmable.
The numbers
| Typical high | 77° |
|---|---|
| Typical low | 66° |
| Days with real rain | 0 |
| Total rain | 0.1 in |
| Humidity | a touch humid |
| Water temperature | 67° |
| Sunrise / sunset (mid-month) | 6:32 am / 6:54 pm |