Early autumn · Weather & things to do
San Antonio in September
San Antonio cools off: highs slip to 90°F (32°C), from 98°F in August, with lows of 70°F (21°C) and about 3.7 in (95 mm) of rain.
Our comfort score puts it mid-table at 67/100, 8th of 12.
- Avg high
- 90°F (32°C)
- Avg low
- 70°F (21°C)
- Rain
- 3.7 in (95 mm)
- Humidity
- 68%
- Cloud cover
- 46%
- Daylight
- ~12 h 10 min
- Comfort score
- 67/100 · Good
What September feels like
Afternoons run hot at about 90°F (32°C), which leaves mornings and evenings as the time for walking.
Nights cool to an average low of 70°F (21°C).
Showers are part of the month, adding up to about 3.7 in (95 mm).
Plan around September
September sits mid-table; the best months are October – March.
- Comfort improves from 56/100 in August to 67/100.
- Our Texas BBQ Trail route recommends Oct – Apr, so September falls outside its suggested window.
- Our San Antonio & the Texas Hill Country route is planned for Late Nov – Dec, a window set by the holiday season rather than the weather — September falls outside it.
What to pack for September
- Light, breathable clotheshighs average 90°F
- Sunscreen, sunglasses and a hatstrong sun this month
- Refillable water bottleeasy to dehydrate in the heat
- Packable rain jacket or umbrellaa shower or two is likely
- Comfortable walking shoesmost places below are best reached on foot or with short walks
What to do in San Antonio in September
Start early and take shelter at midday: the picks below pair morning outings with places to cool off.
Mission San José
Largest of the four missions in San Antonio Missions National Historical Park.
Why now September scores 67/100 for comfort, good conditions for being outside.
River Walk
Stone-lined walkways along the San Antonio River, with cypress trees and bridges strung with lights through the holidays.
Why now Highs near 90°F and 3.7 in of monthly rain make this an easy outdoor pick.
San Antonio River Walk
Below-street paths along the river; take a GO RIO boat for an overview.
Why now One to do outside while the weather is on your side.
The Pearl
Restored brewery complex with restaurants, shops and a weekend farmers market.
Why now A break from 90°F afternoons.
Mi Tierra Café y Panadería
24-hour Tex-Mex restaurant and bakery in Market Square since 1941.
Why now Go early — afternoons average 90°F.
Sternewirth
Hotel Emma's bar in the old brewhouse, with intimate booths in vintage tanks.
Why now Somewhere to sit out the hottest hours.
Nearby in September
- Texas Hill Country in September~58 mi · highs 88°F, 3.4 in rain · 1°C (3°F) cooler by day, about as wet
- Austin in September~74 mi · highs 90°F, 3.4 in rain · similar daytime temperatures, about as wet
- Downtown Houston in September~189 mi · highs 89°F, 4.6 in rain · similar daytime temperatures, wetter
- Dallas in September~252 mi · highs 90°F, 3.0 in rain · similar daytime temperatures, drier
These averages also cover Downtown San Antonio & Hemisfair and Pearl & Museum Reach.
NASA POWER 2001–2025 monthly averages on a ~50 km grid. Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
San Antonio in September: quick answers
Is September a good time to visit San Antonio?
It's middling, scoring 67/100. The best months are October – March, at up to 92. Expect highs of 90°F (32°C) and 3.7 in (95 mm) of rain. Our Texas BBQ Trail route recommends Oct – Apr, so September is outside its suggested window.
How hot is San Antonio in September?
Average highs are 90°F (32°C) and average lows 70°F (21°C), making it the 4th-warmest month by daytime highs.
Does it rain a lot in San Antonio in September?
Some: about 3.7 in (95 mm) of rain falls across September on average, the 2nd-wettest month of the year. The annual total is about 30.7 in (779 mm).
What should I pack for San Antonio in September?
Bring light, breathable clothes (highs average 90°F), sunscreen, sunglasses and a hat (strong sun this month), refillable water bottle (easy to dehydrate in the heat), packable rain jacket or umbrella (a shower or two is likely) and comfortable walking shoes (most places below are best reached on foot or with short walks).
More on San Antonio
Planning San Antonio in September?
Share this September plan with your group, poll everyone on dates and keep the packing list in one place.