Weather in San Marcos, TX
Updated 2026-08-11 12:00 local time · ZIP codes 78666
Cloudy
No government weather alerts were returned for this location at the latest update.
Next hours
90°3% rain
96°2% rain97°2% rain99°2% rain103°1% rain102°1% rain100°1% rain98°1% rain92°1% rain
89°1% rain86°2% rain84°4% rain3-day weather forecast
Weather details
Sunrise, sunset and moon
Weather insights for today
Rain chance stays relatively low over the next 12 hours (up to 4%).
It feels like 96°F with winds near 13 mph.
90°F, 3% rain chance and 13 mph wind.
Visibility is around 10 mi; gusts may reach 29 mph.
Current temperature is 90°F, wind 13 mph, rain chance up to 4%.
UV index is 10. Use shade, sunscreen, a hat and sunglasses.
San Marcos weather today
Cloudy and 90°F in San Marcos, TX. Today's high is 103°F with a 6% rain chance. Winds are around 13 mph with gusts near 15 mph. Relative humidity is 63%, pressure is 30.10 inHg, and visibility is about 10 miles.
Tonight and tomorrow in San Marcos
Sunrise is at 06:57 AM and sunset is at 08:16 PM. Tomorrow's forecast calls for Sunny with a high near 103°F and a low near 75°F. The maximum rain chance is 4%.