San Diego weather in September
San Diego in September averages 22°C (71°F) and 3 mm of rain. It is one of the driest months of the year here.
Of the twelve months in San Diego, September is the second warmest and the fourth driest.
- Average temp
- 22°C (71°F)
19–25°C · 66–77°F
- Rainfall
- 3 mm
Not much rain
- Sunshine
- —
- Wind
- 10 km/h
What is San Diego like in September?
Daytime
Days are mild.
Rain
Rain is usually light.
Evening
Evenings stay warm.
What should I pack for San Diego in September?
Layers for a mild month
Nothing here is extreme — pack for the monthly average and a jacket for the evening.
September compared with August and October
September in San Diego is about the same temperature as August and about as wet as it, which averages 22°C (72°F).
September in San Diego is 2.1°C warmer than October and 10 mm drier than it, which averages 20°C (68°F).
Daylight in San Diego in September
On 15 September the sun is up for 12 hours 21 minutes in San Diego, rising about 06:32 and setting about 18:53 local time.
September ends 58 minutes shorter than it begins, so the last week of the month is a different length of day from the first.
That is 1 hour 57 minutes short of June, the longest-lit month here.
Where to stay in San Diego
Dates are a starting point for September.
Travel guides for San Diego
What to read before you book.
San Diego weather by month
TemperatureRainfall
How September compares with the rest of the year
September is highlighted. Every other month links to its own page.
| Month | Average | Rainfall |
|---|---|---|
| January | 14°C / 58°F | 50 mm |
| February | 15°C / 59°F | 56 mm |
| March | 16°C / 60°F | 37 mm |
| April | 17°C / 62°F | 17 mm |
| May | 18°C / 64°F | 7 mm |
| June | 19°C / 67°F | 1 mm |
| July | 21°C / 70°F | 2 mm |
| August | 22°C / 72°F | 0 mm |
| September | 22°C / 71°F | 3 mm |
| October | 20°C / 68°F | 13 mm |
| November | 17°C / 62°F | 20 mm |
| December | 14°C / 58°F | 42 mm |
Check another month
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FAQs about San Diego in September
September climate averages for San Diego, 1991–2020.
San Diego averages 22°C (71°F) in September, ranging from about 19°C (66°F) at night to 25°C (77°F) in the afternoon. That is a 1991–2020 average, so an individual week can run either side of it.
Barely. September sees only about 3 mm, so rain is unlikely to affect your plans.
Yes. September averages 22°C (71°F) against 20°C (68°F) in October — 2.1°C warmer.
September is about as warm as August, and about as wet.
Yes. September falls inside the most comfortable stretch of the year here, May to October, on temperature and rainfall together.
This page does not show today's weather. It is a 1991–2020 climate normal from Meteostat — a long-run average of what September is usually like, which is what you want when booking months ahead. For today or the coming week, check a live forecast.
About 12 hours 21 minutes of daylight in mid-September, against 14 hours 18 minutes in June and 10 hours 1 minute in December.
On 15 September, sunrise is about 06:32 and sunset about 18:53 local time. Both shift across the month — the month ends 58 minutes shorter than it starts.
