S
M
T
W
T
F
S
30
88°
63°
31
93°
68°
1
95°
67°
2
95°
68°
3
96°
70°
4
97°
71°
5
90°
68°
6
82°
63°
7
84°
58°
8
89°
63°
9
92°
69°
10
84°
68°
11
82°
63°
12
81°
68°
13
89°
64°
14
76°
56°
15
92°
58°
16
92°
70°
17
93°
70°
18
80°
62°
19
88°
69°
20
84°
63°
21
81°
63°
22
81°
62°
23
80°
60°
24
78°
55°
25
74°
55°
26
78°
53°
27
75°
55°
28
76°
49°
29
78°
55°
30
79°
55°
1
76°
54°
2
78°
54°
3
78°
53°
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 74° to 93°, with overnight lows between 49° and 70°. The average high for September is 81° with an average low of 59°. 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.
