SAN MARCOS, TX 78666 Weather Forecast & Current Conditions

Enter ZIP code or City, State   
    


SAN MARCOS, TX
Current Weather

12:56 AM CST DEC 21, 2025
Overcast
55°F
Feels Like: 55°F
Dewpoint: 55°F
Rel. Hum.: 100%
Visibility: 10 miles
Wind: Calm
Pressure: 30.02 inches
Last 72 hours

Local Area Snow Depth

Texas Current Weather

Texas MOS Forecast Weather


Weather Map


(Automated weather data from NWS/FAA)
10-Day model forecast maps
2025 Hurricanes

SAN MARCOS, TX 78666
Weather Forecast

Snowfall Forecast pages
Snow Depth pages
REST OF TONIGHT
Mostly clear. Lows in the upper 40s. Northwest winds 5 to 10 mph.
SUNDAY
Mostly sunny in the morning, then becoming partly cloudy. Highs in the upper 60s. North winds 5 to 10 mph with gusts up to 20 mph.
SUNDAY NIGHT
Partly cloudy in the evening, then becoming mostly cloudy. Lows around 50. North winds around 5 mph.
MONDAY
Mostly cloudy in the morning, then becoming partly cloudy. More humid with highs in the mid 70s. Southeast winds around 5 mph, becoming south with gusts up to 20 mph in the afternoon.
MONDAY NIGHT
Partly cloudy in the evening, then becoming cloudy. Not as cool with lows in the lower 60s. South winds 5 to 10 mph.
TUESDAY
Cloudy in the morning, then becoming partly cloudy. Highs in the upper 70s.
TUESDAY NIGHT
Partly cloudy in the evening, then becoming mostly cloudy. Lows around 60.
WEDNESDAY
Cloudy in the morning, then becoming partly cloudy. Highs in the upper 70s.
WEDNESDAY NIGHT
Partly cloudy in the evening, then becoming mostly cloudy. Lows around 60.
CHRISTMAS DAY
Cloudy in the morning, then becoming partly cloudy. Highs in the upper 70s.
THURSDAY NIGHT THROUGH SATURDAY
Partly cloudy. Lows around 60. Highs in the lower 80s.

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  7:00 PM EST 12/20/2025
Sunday
21 DEC 2025
SAN MARCOS, TX 78666 weather forecast Day 1, 0 hours 12 AM 58° 57° Partly Cloudy 0%

0% Thunder
( 1% severe)
SW   6 96% 57°
Low 51° SAN MARCOS, TX 78666 weather forecast Day 1, 3 hours 3 AM 56° 55° Partly Cloudy NW   6 93% 54°
High 72° SAN MARCOS, TX 78666 weather forecast Day 1, 6 hours 6 AM 52° 49° Clear 0%

0% Thunder
( 0% severe)
N   8 77% 45°

Partly Cloudy



SAN MARCOS, TX 78666 weather forecast Day 1, 9 hours 9 AM 56° 54° Partly Cloudy N   9 62% 43°
SAN MARCOS, TX 78666 weather forecast Day 1, 12 hours 12 PM 67° 67° Partly Cloudy 0%

0% Thunder
( 0% severe)
N   9 47% 46°
SAN MARCOS, TX 78666 weather forecast Day 1, 15 hours 3 PM 71° 71° Partly Cloudy N   8 42% 47°
SAN MARCOS, TX 78666 weather forecast Day 1, 18 hours 6 PM 64° 64° Partly Cloudy 1%

0% Thunder
( 0% severe)
NNE   7 56% 48°
SAN MARCOS, TX 78666 weather forecast Day 1, 21 hours 9 PM 57° 57° Partly Cloudy N   3 75% 49°
Monday
22 DEC 2025
SAN MARCOS, TX 78666 weather forecast Day 2, 0 hours 12 AM 55° 55° Mostly Cloudy 2%

0% Thunder
( 1% severe)
N   3 83% 50°
Low 51° SAN MARCOS, TX 78666 weather forecast Day 2, 3 hours 3 AM 55° 55° Mostly Cloudy N   2 86% 51°
High 77° SAN MARCOS, TX 78666 weather forecast Day 2, 6 hours 6 AM 55° 55° Mostly Cloudy 3%

0% Thunder
( 1% severe)
NNE   2 90% 52°

Mostly Cloudy



SAN MARCOS, TX 78666 weather forecast Day 2, 9 hours 9 AM 61° 62° Mostly Cloudy NNE   3 87% 57°
SAN MARCOS, TX 78666 weather forecast Day 2, 12 hours 12 PM 70° 70° Mostly Cloudy 2%

0% Thunder
( 1% severe)
S   7 76% 62°
SAN MARCOS, TX 78666 weather forecast Day 2, 15 hours 3 PM 75° 75° Mostly Cloudy S   10 69% 64°
SAN MARCOS, TX 78666 weather forecast Day 2, 18 hours 6 PM 72° 72° Partly Cloudy 1%

0% Thunder
( 1% severe)
S   8 73% 63°
SAN MARCOS, TX 78666 weather forecast Day 2, 21 hours 9 PM 68° 68° Partly Cloudy SSE   8 87% 64°

SAN MARCOS, TX extended weather forecast

Tuesday
23 DEC 2025
Wednesday
24 DEC 2025
Thursday
25 DEC 2025
Friday
26 DEC 2025
Saturday
27 DEC 2025
Low 58° Low 59° Low 61° Low 60° Low 57°
High 80° High 80° High 80° High 82° High 80°
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
Partly Cloudy
5% Rain
Mostly Cloudy
13% Rain
Partly Cloudy
21% Rain
Mostly Cloudy
19% Rain
Partly Cloudy
18% Rain
SELECT BOX EXAMPLES:
for LOCAL WEATHER:
SNOW DEPTH:
LOCAL WEATHER RADAR:
STATE WEATHER MAP:
San Marcos, TX
San Marcos, TX snow
San Marcos, TX radar
TX map
-or-
-or-
-or-
 
78666
78666 snow
78666 radar
 
-or-
-or-
 
 
TX
TX snow
 
 
Copyright © 2024 WeatherStreet.com
Put our free WeatherStreet weather lookup on your web page.
Terms & Conditions