S
M
T
W
T
F
S
30
86°
61°
31
84°
54°
1
82°
53°
2
79°
55°
3
79°
54°
4
80°
54°
5
79°
55°
6
78°
53°
7
77°
53°
8
78°
56°
9
78°
53°
10
76°
52°
11
77°
54°
12
79°
53°
13
78°
52°
14
77°
51°
15
75°
53°
16
75°
49°
17
76°
50°
18
76°
50°
19
74°
55°
20
75°
54°
21
77°
47°
22
72°
46°
23
Hist. Avg.
74°
50°
24
Hist. Avg.
74°
50°
25
Hist. Avg.
73°
50°
26
Hist. Avg.
73°
49°
27
Hist. Avg.
72°
49°
28
Hist. Avg.
72°
48°
29
Hist. Avg.
72°
48°
30
Hist. Avg.
71°
48°
1
Hist. Avg.
71°
47°
2
Hist. Avg.
70°
47°
3
Hist. Avg.
70°
46°
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 72° to 86°, with overnight lows between 46° and 61°. The average high for September is 78° with an average low of 53°. 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.
