S
M
T
W
T
F
S
30
88°
76°
31
90°
76°
1
90°
74°
2
88°
75°
3
89°
75°
4
90°
74°
5
87°
75°
6
87°
75°
7
86°
74°
8
86°
75°
9
88°
72°
10
89°
71°
11
87°
71°
12
88°
72°
13
87°
71°
14
85°
70°
15
86°
71°
16
86°
71°
17
85°
70°
18
88°
72°
19
86°
72°
20
89°
73°
21
89°
72°
22
Hist. Avg.
87°
72°
23
Hist. Avg.
87°
72°
24
Hist. Avg.
87°
72°
25
Hist. Avg.
87°
71°
26
Hist. Avg.
86°
71°
27
Hist. Avg.
86°
71°
28
Hist. Avg.
86°
70°
29
Hist. Avg.
86°
70°
30
Hist. Avg.
86°
70°
1
Hist. Avg.
85°
70°
2
Hist. Avg.
85°
69°
3
Hist. Avg.
85°
69°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Fairfax
Fairfax's September 2026 forecast shows daily high temperatures ranging from 85° to 90°, with overnight lows between 70° and 76°. The average high for September is 88° with an average low of 73°. 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 Fairfax. See also: October | November | December.
