San Antonio Weather in September
September is one of the perfect months to visit San Antonio, with daytime temperatures of 28°C (82°F) and lows of 22°C (72°F) at night. Some rainfall is typical for this time of year.
Rainfall in San Antonio in September
You can typically expect 6 days of rain this month, averaging around 45 mm (1.8 in). Rainfall tends to arrive in short, intense showers this month. Rain days are few, but the showers can be surprisingly heavy.
Temperature in San Antonio in September
September is a good time to be in San Antonio. Days are perfect, reaching 28°C (82°F), with nights around 22°C (72°F). This kind of day-to-night contrast is typical for this time of year. With overnight lows of 22°C (72°F), evenings stay pleasantly warm.
Sunshine in San Antonio in September
Expect sunny days throughout the month, with an estimated 240 hours of sunshine. This makes it a pleasant time to visit San Antonio.
Average water temperature in September
The water temperature is 25°C (77°F), which most people find very comfortable. A good month for swimming and water sports.If you're inclined towards comfortable temperatures and drier conditions, September is a good time to visit San Antonio.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Spain, check out our San Antonio's climate page.
San Antonio Temperature in September
Min Temperature
22°C (72°F)
Max Temperature
28°C (82°F)
Water Temperature
25°C (77°F) *
Chance of Rain
21%
Precipitation
45 mm (1.8 in)
Rainy days
6 days
Humidity
72% *
Sunshine
240 hours *
Percentage Sunshine
63% *
Daily Historical Temperatures
49-year average (1976-2025)
Based on our historical records, temperatures in San Antonio typically drop from around 29°C (84°F) at the start of September to approximately 26°C (79°F) by the end. Nights are warm, with lows typically ranging from 18°C (64°F) to 22°C (72°F).
Average temperatures in September
Daily Historical Precipitation
49-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for San Antonio in September
Browse day-by-day weather records for San Antonio spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
San Antonio historical weather extremes in September
According to our 27 years of weather records for San Antonio, the following extremes were recorded between 1998 and 2025.
- On September 5, 2016, temperatures climbed to 37°C (99°F), marking the warmest September day on record.
- On September 18, 2005, San Antonio saw its coldest September day with temperatures maxing out at 20°C (68°F).
- The lowest overnight temperature recorded in September was 13°C (55°F) (September 28, 2007).
Best Places in Spain in September
Find out more about the weather in Spain and which places have the best travel conditions in this month. See all of Spain in September →
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What to Wear in San Antonio in September
Warm temperatures in September make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. Rain gear is recommended, you can expect wet weather on multiple days. With water temperatures around 25°C (77°F), swimming conditions are excellent. Pack your swimsuit, goggles, and maybe some water shoes. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in San Antonio in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Spain, check out our San Antonio's climate page.
Temperature Rainfall Sunshine Humidity Water Temp
See the full San Antonio climate overview or explore weather in Spain.
