S
M
T
W
T
F
S
30
92°
70°
31
89°
65°
1
86°
61°
2
84°
58°
3
86°
61°
4
87°
63°
5
91°
69°
6
86°
65°
7
89°
67°
8
93°
66°
9
97°
68°
10
88°
64°
11
85°
61°
12
84°
62°
13
84°
64°
14
86°
63°
15
87°
64°
16
89°
61°
17
91°
64°
18
83°
58°
19
84°
59°
20
87°
61°
21
89°
63°
22
87°
63°
23
86°
62°
24
85°
60°
25
85°
62°
26
89°
63°
27
88°
63°
28
88°
62°
29
87°
63°
30
88°
61°
1
87°
62°
2
86°
61°
3
84°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in San Dimas
San Dimas's September 2026 forecast shows daily high temperatures ranging from 83° to 97°, with overnight lows between 58° and 69°. The average high for September is 87° with an average low of 63°. 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 Dimas. See also: October | November | December.
