Hourly Weather | Tomorrow Thursday, March 19, 2026
Active Weather Warnings
San Marcos, California
12 AM
Cloudy Night
61°
Feels Like 61°
0
Humidity: 75%
UV Index: 0
Wind: 4 mph
1 AM
Cloudy Night
57°
Feels Like 57°
0
Humidity: 80%
UV Index: 0
Wind: 4 mph
2 AM
Cloudy Night
55°
Feels Like 55°
0
Humidity: 82%
UV Index: 0
Wind: 4 mph
3 AM
Cloudy Night
54°
Feels Like 54°
0
Humidity: 84%
UV Index: 0
Wind: 4 mph
4 AM
Cloudy Night
52°
Feels Like 52°
0
Humidity: 88%
UV Index: 0
Wind: 4 mph
5 AM
Cloudy Night
54°
Feels Like 54°
0
Humidity: 82%
UV Index: 0
Wind: 4 mph
6 AM
Cloudy Night
54°
Feels Like 54°
0
Humidity: 79%
UV Index: 0
Wind: 4 mph
7 AM
Cloudy Weather
54°
Feels Like 55°
0
Humidity: 77%
UV Index: 0
Wind: 4 mph
8 AM
Cloudy Weather
61°
Feels Like 63°
0
Humidity: 62%
UV Index: 1
Wind: 4 mph
9 AM
Cloudy Weather
68°
Feels Like 70°
0
Humidity: 48%
UV Index: 2
Wind: 5 mph
10 AM
Sunny Weather
75°
Feels Like 79°
0
Humidity: 39%
UV Index: 3
Wind: 6 mph
11 AM
Sunny Weather
81°
Feels Like 84°
0
Humidity: 35%
UV Index: 5
Wind: 6 mph
12 PM
Sunny Weather
84°
Feels Like 88°
0
Humidity: 31%
UV Index: 6
Wind: 7 mph
1 PM
Sunny Weather
88°
Feels Like 91°
0
Humidity: 29%
UV Index: 7
Wind: 8 mph
2 PM
Sunny Weather
90°
Feels Like 93°
0
Humidity: 26%
UV Index: 6
Wind: 8 mph
3 PM
Sunny Weather
90°
Feels Like 91°
0
Humidity: 27%
UV Index: 5
Wind: 8 mph
4 PM
Sunny Weather
88°
Feels Like 88°
0
Humidity: 28%
UV Index: 3
Wind: 8 mph
5 PM
Sunny Weather
84°
Feels Like 84°
0
Humidity: 30%
UV Index: 2
Wind: 8 mph
6 PM
Sunny Weather
81°
Feels Like 79°
0
Humidity: 35%
UV Index: 1
Wind: 7 mph
7 PM
Night
75°
Feels Like 73°
0
Humidity: 42%
UV Index: 0
Wind: 5 mph
8 PM
Night
73°
Feels Like 72°
0
Humidity: 48%
UV Index: 0
Wind: 4 mph
9 PM
Cloudy Night
70°
Feels Like 68°
0
Humidity: 54%
UV Index: 0
Wind: 4 mph
10 PM
Cloudy Night
66°
Feels Like 64°
0
Humidity: 61%
UV Index: 0
Wind: 4 mph
11 PM
Cloudy Night
63°
Feels Like 63°
0
Humidity: 66%
UV Index: 0
Wind: 4 mph

Weather Alerts and Warnings for San Marcos

Severe Future Likely

Extreme Heat Watch

Extreme Heat Watch issued March 14 at 5:51AM PDT until March 20 at 8:00PM PDT by NWS San Diego CA
Mar 16, 10:00 AM Mar 20, 8:00 PM
WHAT: Dangerously hot conditions with temperatures 85 to 90 near
the coast, up to 105 inland.

WHERE: Orange County Coastal Areas, Orange County Inland Areas,
San Bernardino and Riverside County Valleys-The Inland Empire, San
Diego County Coastal Areas, San Diego County Valleys, and Santa
Ana Mountains and Foothills.

WHEN: From Monday morning through Friday evening.

IMPACTS: Heat related illnesses increase significantly during
extreme heat events.

ADDITIONAL DETAILS: High temperatures next week will be 20 to
potentially 30 degrees above
normal for this time of year, where record breaking heat is likely.
+ Read More
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes.
Updated: Mar 14, 12:05 PM Source: NWS Alert
Moderate Expected Likely

Heat Advisory

Heat Advisory issued March 18 at 2:49AM PDT until March 20 at 8:00PM PDT by NWS San Diego CA
Mar 18, 2:49 AM Mar 20, 8:00 PM
WHAT: High temperatures in the upper 90s to 104 expected.

WHERE: San Diego County Valleys.

WHEN: Until 8 PM PDT Friday.

IMPACTS: Hot temperatures may cause heat illnesses.
+ Read More
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes. Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke.
Updated: Mar 18, 9:16 AM Source: NWS Alert