S
M
T
W
T
F
S
28
95°
79°
29
96°
79°
30
96°
77°
1
96°
76°
2
97°
73°
3
98°
75°
4
98°
76°
5
96°
76°
6
97°
76°
7
98°
72°
8
99°
76°
9
98°
74°
10
96°
70°
11
87°
74°
12
N/A
13
91°
75°
14
82°
72°
15
81°
73°
16
84°
72°
17
90°
73°
18
93°
74°
19
93°
74°
20
97°
74°
21
96°
75°
22
97°
74°
23
94°
75°
24
94°
74°
25
97°
75°
26
99°
74°
27
99°
76°
28
99°
77°
29
98°
77°
30
99°
76°
31
99°
76°
1
98°
75°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
July Weather in San Marcos
San Marcos's July 2026 forecast shows daily high temperatures ranging from 81° to 99°, with overnight lows between 72° and 77°. The average high for July is 94° with an average low of 75°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how July weather will actually feel in San Marcos. See also: August | September | October.
