S
M
T
W
T
F
S
30
82°
45°
31
77°
43°
1
75°
44°
2
76°
48°
3
78°
45°
4
83°
43°
5
80°
52°
6
78°
49°
7
73°
43°
8
73°
41°
9
74°
42°
10
73°
44°
11
73°
47°
12
77°
46°
13
81°
43°
14
81°
47°
15
80°
51°
16
76°
50°
17
71°
45°
18
71°
50°
19
73°
50°
20
78°
51°
21
79°
50°
22
78°
47°
23
71°
50°
24
75°
42°
25
68°
41°
26
68°
48°
27
69°
45°
28
69°
42°
29
67°
48°
30
72°
49°
1
74°
49°
2
76°
46°
3
75°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Foster
Foster's September 2026 forecast shows daily high temperatures ranging from 67° to 83°, with overnight lows between 41° and 52°. The average high for September is 75° with an average low of 46°. 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 Foster. See also: October | November | December.
