S
M
T
W
T
F
S
30
92°
71°
31
89°
71°
1
88°
70°
2
89°
71°
3
88°
70°
4
89°
69°
5
90°
69°
6
91°
70°
7
92°
69°
8
91°
70°
9
92°
69°
10
92°
69°
11
91°
70°
12
92°
69°
13
92°
71°
14
91°
71°
15
90°
70°
16
90°
70°
17
89°
69°
18
88°
68°
19
88°
69°
20
89°
70°
21
87°
67°
22
88°
68°
23
88°
69°
24
89°
67°
25
88°
65°
26
87°
66°
27
88°
68°
28
89°
67°
29
88°
67°
30
88°
68°
1
86°
65°
2
Hist. Avg.
87°
67°
3
Hist. Avg.
87°
67°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Fairfield
Fairfield's September 2026 forecast shows daily high temperatures ranging from 86° to 92°, with overnight lows between 65° and 71°. The average high for September is 89° with an average low of 69°. 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 Fairfield. See also: October | November | December.
