What September feels like in San Antonio
September is early autumn in San Antonio. The midday hours are hot; shade and water matter on long walks. Evenings bring a clear drop in temperature, and nights stay warm. The air carries some moisture, so hot spells feel a little sticky.
Rain in San Antonio in September
It is a changeable month: rain comes about one day in 3, with dry spells in between. Rainy days are intense, averaging about 9.7 mm (0.4 in) — downpours rather than drizzle. That is close to San Antonio's typical rain per wet day for the whole year (about 8.5 mm). It is among the three wettest months of the year.
Daylight and sunshine in September
On 15 September the sun rises at about 7:18 am and sets around 7:41 pm local time, giving 12 h 23 min of daylight. Days are getting shorter: 51 min less daylight than in mid-August. The sun is out for roughly 84% of those daylight hours, so skies are mostly clear.
How September compares to the rest of the year
September is the 4th warmest month of the year in San Antonio. Afternoons run 3.5°C (6.3°F) cooler than in August, with 32 mm more rain. Temperatures keep falling into October. The next month's average high: 28.2°C (82.8°F).
Who September suits
- Sightseeing: less ideal — midday heat makes long walks hard.
- Parks & outdoor: less ideal — afternoons are too warm to linger outside.
- Museums & indoor: a good choice — a cool break during the hottest hours.
Tips for visiting San Antonio in September
Rain Protection
Keep a small umbrella in your bag and wear shoes that cope with puddles.
Sun Protection
Sunscreen, a hat and sunglasses; light breathable clothes.
Quick questions
How warm is San Antonio in September?
Afternoons average 32.2°C (90°F) and nights about 22.5°C (72.5°F) — hot by most people's standards. It is the 4th warmest month of the year.
Does it rain a lot in San Antonio in September?
Quite a lot — 87 mm spread over about 9 days.
What should I wear in San Antonio in September?
Pack rain protection and sun protection. There is little need to change for the evening.
Is September or October better for visiting San Antonio?
October scores better on our climate ranking (#5 of 12 vs #12), rated Good against Fair. October is cooler and has fewer rainy days.