San Diego Weather in September
“The kind of pleasant weather you build a trip around.”
Roughly 2 rainy days across the month, on average.
September is widely considered one of the finest months to experience San Diego. The summer rush begins to ease, yet the climate stays gloriously warm, with average afternoon highs reaching a pleasant 25.5°C and mild evening lows hovering around 18.4°C.
With roughly 10.7 hours of bright sunshine daily and a negligible 14mm of rainfall spread across just 1.5 days, outdoor plans are virtually guaranteed to remain dry and sun-drenched. It is the golden hour of the Southern California coast, offering tranquil beach conditions and gentle Pacific breezes.
What to pack for San Diego in September
- Breathable cotton or linen shirts for warm, sunny afternoons
- Light knit sweater or denim jacket for cooler coastal evenings
- Polarized sunglasses and a wide-brim sun hat
- Comfortable walking sneakers or supportive sandals
- Swimwear and high-SPF sunscreen for beach outings
What to pack for San Diego in September
- →Breathable travel pantsAmazon · shop this
- →Reef-safe sunscreen SPF 50Amazon · shop this
- →Polarized sunglassesAmazon · shop this
- →Universal travel adapterAmazon · shop this
- →Compression packing cubesAmazon · shop this
- →Anti-theft crossbody bagAmazon · shop this
We may earn a small commission on any purchase — it doesn't change the price you pay.
Where to stay in San Diego
We don't review individual hotels — plenty of people do that well. What we do is send you to compare rooms in San Diego across trusted platforms.
Compare hotels on Booking.com→Things worth doing
Spend peaceful afternoons swimming, paddleboarding, or sunbathing along the shores of La Jolla and Coronado. Take advantage of the clear, dry days by wandering through the shaded trails and museums of Balboa Park, or enjoy an open-air harbor cruise at sunset.
September vs. the rest of the year
How this month compares in San Diego. Tap any month to read more.
highlighted months are among the best time to visit.
Best time to visit San Diego
While September has its own character in San Diego, the data-backed best months to visit San Diego are April, June, July, August. These months combine the most favourable temperatures, rainfall, and sunshine across a ten-year climate record.
See the full best-time-to-visit guide for San DiegoOther places with a similar climate right now
San Diego in September — FAQ
Q01Is September a good time to visit San Diego?
Is September a good time to visit San Diego?
Yes — this is one of the best months of the year to visit. In September, San Diego averages a high of 26°C (78°F) and a low of 18°C (65°F), with 14mm of rainfall across roughly 2 rainy days.
Q02What is the average temperature in San Diego in September?
What is the average temperature in San Diego in September?
The average high temperature in San Diego during September is 26°C (78°F), with an average low of 18°C (65°F). These figures are averaged from ten years of daily records (2015–2024, Open-Meteo Archive).
Q03How many rainy days does San Diego have in September?
How many rainy days does San Diego have in September?
San Diego averages approximately 2 rainy days in September, with a total monthly rainfall of about 14mm. This is based on daily precipitation records where days with 1mm or more of rain are counted as rainy days.
Q04What should I pack for San Diego in September?
What should I pack for San Diego in September?
For San Diego in September, pack layered clothing for changing temperatures, sunscreen and sunglasses, comfortable walking shoes. These recommendations are based on the ten-year weather averages for this specific month.
Q05How crowded is San Diego in September?
How crowded is San Diego in September?
Tourist crowds in San Diego during September are typically moderate — shoulder season, a sweet spot between crowds and weather. Consider this when planning accommodation — prices track crowd levels closely.