S
M
T
W
T
F
S
30
74°
46°
31
71°
51°
1
73°
55°
2
71°
50°
3
76°
55°
4
79°
48°
5
77°
46°
6
70°
46°
7
70°
44°
8
69°
49°
9
73°
51°
10
72°
44°
11
68°
42°
12
67°
43°
13
68°
45°
14
67°
43°
15
66°
42°
16
65°
42°
17
65°
40°
18
63°
40°
19
64°
41°
20
64°
40°
21
65°
40°
22
67°
44°
23
70°
47°
24
70°
44°
25
69°
48°
26
71°
42°
27
70°
37°
28
61°
45°
29
61°
45°
30
69°
42°
1
67°
43°
2
66°
44°
3
63°
36°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Tustin
Tustin's September 2026 forecast shows daily high temperatures ranging from 61° to 79°, with overnight lows between 36° and 55°. The average high for September is 69° with an average low of 45°. 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 Tustin. See also: October | November | December.
