S
M
T
W
T
F
S
30
61°
53°
31
61°
53°
1
68°
52°
2
62°
51°
3
61°
51°
4
60°
53°
5
61°
49°
6
62°
50°
7
58°
53°
8
60°
51°
9
61°
51°
10
60°
50°
11
57°
48°
12
58°
49°
13
60°
52°
14
60°
54°
15
Hist. Avg.
62°
48°
16
Hist. Avg.
62°
47°
17
Hist. Avg.
61°
47°
18
Hist. Avg.
61°
47°
19
Hist. Avg.
61°
47°
20
Hist. Avg.
61°
46°
21
Hist. Avg.
60°
46°
22
Hist. Avg.
60°
46°
23
Hist. Avg.
60°
45°
24
Hist. Avg.
60°
45°
25
Hist. Avg.
60°
45°
26
Hist. Avg.
59°
45°
27
Hist. Avg.
59°
44°
28
Hist. Avg.
59°
44°
29
Hist. Avg.
59°
44°
30
Hist. Avg.
59°
44°
1
Hist. Avg.
59°
43°
2
Hist. Avg.
58°
43°
3
Hist. Avg.
58°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Mainland
Mainland's September 2026 forecast shows daily high temperatures ranging from 57° to 68°, with overnight lows between 48° and 54°. The average high for September is 61° with an average low of 51°. 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 Mainland. See also: October | November | December.
