San Marcos, TX Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for San Marcos, a city in Hays County, Texas.
Today
99°F
Sunny
Sunny, with a high near 99. Heat index values as high as 104. South wind 5 to 10 mph.
7-day forecast for San Marcos
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 99°F | Sunny | 5 to 10 mph S | 3% |
| Tonight | 76°F | Mostly Clear | 5 to 10 mph S | 3% |
| Wednesday | 98°F | Mostly Sunny | 5 to 10 mph S | 2% |
| Wednesday Night | 76°F | Mostly Clear | 5 to 10 mph S | 1% |
| Thursday | 98°F | Mostly Sunny | 5 mph S | 3% |
| Thursday Night | 76°F | Mostly Clear | 5 to 10 mph SSE | 3% |
| Friday | 96°F | Mostly Sunny | 0 to 5 mph S | 7% |
| Friday Night | 75°F | Partly Cloudy | 0 to 5 mph SSE | 7% |
| Saturday | 95°F | Mostly Sunny | 0 to 5 mph SSE | 3% |
| Saturday Night | 75°F | Mostly Clear | 0 to 5 mph SSE | 4% |
| Sunday | 95°F | Sunny | 0 to 10 mph S | 5% |
| Sunday Night | 75°F | Mostly Clear | 5 to 10 mph SSE | 5% |
| Monday | 96°F | Mostly Sunny | 0 to 10 mph S | 5% |
| Monday Night | 76°F | Mostly Clear | 5 to 10 mph SSE | 5% |
Forecast source: National Weather Service (api.weather.gov) for San Marcos (29.872, -97.936). Updated through the day.
Growing snapshot for San Marcos
Last spring frost
Feb 28
First fall frost
Nov 29
Growing season
273 days
Hardiness zone
9a
More local growing data for San Marcos: nearby ZIP 78666 weather · frost dates · planting calendar · Texas frost dates
Nearby towns & communities
Bear Creek
Belterra
Buda
Driftwood
Dripping Springs
Kyle
Mountain City
Niederwald
Uhland
Wimberley
Woodcreek
Climate data from the nearest NOAA station, San Marcos, Tx (2.1 mi from San Marcos). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.