SAN MARCOS, TX 78666 Weather Forecast & Current Conditions

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SAN MARCOS, TX
Current Weather

6:56 AM CDT SEP 4, 2025
Clear
64°F
Feels Like: 64°F
Dewpoint: 57°F
Rel. Hum.: 78%
Visibility: 10 miles
Wind: Calm
Pressure: 29.93 inches
Last 72 hours

Local Area Snow Depth

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SAN MARCOS, TX 78666
Weather Forecast

Snowfall Forecast pages
Snow Depth pages
TODAY
Mostly sunny. Hot with highs around 101. Southwest winds around 5 mph, becoming southeast around 5 mph this afternoon.
TONIGHT
Partly cloudy. Lows in the lower 70s. South winds 5 to 10 mph.
FRIDAY
Partly cloudy. Highs in the upper 90s. South winds 5 to 10 mph.
FRIDAY NIGHT
Mostly cloudy. Lows in the lower 70s. Southeast winds 5 to 10 mph.
SATURDAY
Mostly cloudy with a slight chance of showers in the morning, then partly cloudy with a chance of showers with a slight chance of thunderstorms in the afternoon. Highs in the lower 90s. Northeast winds 5 to 10 mph. Chance of rain 30 percent.
SATURDAY NIGHT
Partly cloudy in the evening, then becoming mostly cloudy. A slight chance of thunderstorms. A slight chance of showers in the evening, then a chance of showers after midnight. Lows in the lower 70s. Chance of rain 30 percent.
SUNDAY
Mostly cloudy. A chance of showers in the morning, then showers likely with a chance of thunderstorms in the afternoon. Highs in the upper 80s. Chance of rain 60 percent.
SUNDAY NIGHT
Mostly cloudy in the evening, then becoming partly cloudy. A chance of showers. A chance of thunderstorms, mainly in the evening. Lows in the upper 60s. Chance of rain 50 percent.
MONDAY
Partly cloudy with a chance of showers. A slight chance of thunderstorms in the afternoon. Highs in the mid 80s. Chance of rain 40 percent.
MONDAY NIGHT
Partly cloudy in the evening, then becoming mostly clear. Lows in the mid 60s.
TUESDAY
Mostly sunny in the morning, then partly cloudy with a slight chance of showers and thunderstorms in the afternoon. Highs around 90.
TUESDAY NIGHT AND WEDNESDAY
Mostly clear. Lows in the mid 60s. Highs in the lower 90s.

Visible Weather Satellite
SAN MARCOS, TX 78666
Infrared Weather Satellite
SAN MARCOS, TX 78666
NEXRAD Weather Radar
SAN MARCOS, TX 78666

SAN MARCOS, TX 3 hourly weather forecast

weather forecast created  8:00 PM EDT  9/ 3/2025
Thursday
4 SEP 2025
SAN MARCOS, TX 78666 weather forecast Day 1, 0 hours 1 AM 75° 75° Clear 0%

0% Thunder
( 0% severe)
NE   1 58% 59°
Low 67° SAN MARCOS, TX 78666 weather forecast Day 1, 3 hours 4 AM 72° 72° Partly Cloudy WNW   1 66% 60°
High 103° SAN MARCOS, TX 78666 weather forecast Day 1, 6 hours 7 AM 68° 68° Clear 0%

0% Thunder
( 1% severe)
W   2 78% 61°

Clear



SAN MARCOS, TX 78666 weather forecast Day 1, 9 hours 10 AM 86° 89° Clear SW   3 53% 67°
SAN MARCOS, TX 78666 weather forecast Day 1, 12 hours 1 PM 98° 98° Clear 0%

0% Thunder
( 9% severe)
SSW   3 29% 60°
SAN MARCOS, TX 78666 weather forecast Day 1, 15 hours 4 PM 100° 99° Partly Cloudy SSE   2 24% 57°
SAN MARCOS, TX 78666 weather forecast Day 1, 18 hours 7 PM 97° 96° Partly Cloudy 0%

0% Thunder
( 4% severe)
SE   6 27% 57°
SAN MARCOS, TX 78666 weather forecast Day 1, 21 hours 10 PM 86° 86° Partly Cloudy SSE   6 43% 61°
Friday
5 SEP 2025
SAN MARCOS, TX 78666 weather forecast Day 2, 0 hours 1 AM 80° 82° Partly Cloudy 0%

0% Thunder
( 1% severe)
S   8 65% 67°
Low 73° SAN MARCOS, TX 78666 weather forecast Day 2, 3 hours 4 AM 76° 77° Mostly Cloudy SSW   8 79% 69°
High 101° SAN MARCOS, TX 78666 weather forecast Day 2, 6 hours 7 AM 73° 73° Partly Cloudy 0%

0% Thunder
( 1% severe)
SSW   7 90% 70°

Partly Cloudy



SAN MARCOS, TX 78666 weather forecast Day 2, 9 hours 10 AM 85° 90° Partly Cloudy SSW   10 63% 71°
SAN MARCOS, TX 78666 weather forecast Day 2, 12 hours 1 PM 96° 100° Partly Cloudy 1%

0% Thunder
( 11% severe)
S   10 38% 66°
SAN MARCOS, TX 78666 weather forecast Day 2, 15 hours 4 PM 98° 99° Mostly Cloudy SSE   8 31% 62°
SAN MARCOS, TX 78666 weather forecast Day 2, 18 hours 7 PM 95° 96° Partly Cloudy 1%

0% Thunder
( 5% severe)
SE   8 35% 63°
SAN MARCOS, TX 78666 weather forecast Day 2, 21 hours 10 PM 85° 88° Mostly Cloudy SSE   9 55% 67°

SAN MARCOS, TX extended weather forecast

Saturday
6 SEP 2025
Sunday
7 SEP 2025
Monday
8 SEP 2025
Tuesday
9 SEP 2025
Wednesday
10 SEP 2025
Low 72° Low 69° Low 71° Low 70° Low 71°
High 89° High 91° High 89° High 93° High 96°
SAN MARCOS, TX 78666 weather forecast Day 3 SAN MARCOS, TX 78666 weather forecast Day 4 SAN MARCOS, TX 78666 weather forecast Day 5 SAN MARCOS, TX 78666 weather forecast Day 6 SAN MARCOS, TX 78666 weather forecast Day 7
Overcast
30% Rain
Overcast
32% Rain
Overcast
55% Rain
Mostly Cloudy
17% Rain
Clear
9% Rain
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