S
M
T
W
T
F
S
30
100°
72°
31
97°
72°
1
100°
72°
2
101°
72°
3
100°
72°
4
100°
73°
5
N/A
6
93°
74°
7
93°
74°
8
93°
74°
9
93°
74°
10
91°
75°
11
92°
74°
12
93°
69°
13
94°
71°
14
95°
70°
15
90°
75°
16
87°
75°
17
89°
74°
18
92°
72°
19
92°
72°
20
93°
71°
21
92°
72°
22
92°
72°
23
91°
71°
24
91°
72°
25
92°
72°
26
91°
71°
27
91°
72°
28
92°
72°
29
91°
70°
30
91°
71°
1
92°
70°
2
92°
71°
3
93°
71°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in San Luis
San Luis's September 2026 forecast shows daily high temperatures ranging from 87° to 95°, with overnight lows between 69° and 75°. The average high for September is 92° with an average low of 72°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in San Luis. See also: October | November | December.
