San Antonio weather in December
December in San Antonio: nice, dry, with clean air — an excellent time to visit.
#3 of 12 months in San Antonio · #98 of 604 destinations to visit in December · comfort 84/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
San Antonio climate normals — December
| Daytime high | 20°C / 68°F | 😎 nice |
|---|---|---|
| Nighttime low | 10°C / 49°F | |
| Feels like (high) | 19°C / 66°F | |
| Rainfall | 29 mm / 1.1 in | ☀️ dry |
| Rainy days | 6 days | |
| Humidity | 69% | 💧 humid |
| Dew point | 7°C / 45°F | |
| Sunshine | 7.1 h/day | |
| Daylight | 10.3 h | |
| Wind | 17 km/h / 10 mph | |
| Air quality (US AQI) | 31 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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San Antonio in December — FAQ
- Is December a good time to visit San Antonio?
- December in San Antonio: nice, dry, with clean air — an excellent time to visit. It ranks #3 of 12 months for San Antonio on SeasonMap's comfort score (84/100).
- What is the weather like in San Antonio in December?
- In December, San Antonio averages a daily high of 20.1°C and a low of 9.6°C, with about 28.9 mm of rain over roughly 6 rainy days.
- What is the air quality in San Antonio in December?
- San Antonio has a mean US Air Quality Index of about 31 in December.