S
M
T
W
T
F
S
30
87°
68°
31
83°
57°
1
83°
63°
2
80°
67°
3
85°
66°
4
86°
64°
5
87°
65°
6
81°
58°
7
76°
58°
8
77°
55°
9
76°
55°
10
74°
53°
11
74°
51°
12
78°
57°
13
75°
57°
14
77°
56°
15
78°
55°
16
74°
54°
17
76°
56°
18
75°
54°
19
74°
53°
20
75°
54°
21
77°
55°
22
76°
55°
23
76°
54°
24
77°
55°
25
76°
54°
26
75°
52°
27
76°
53°
28
76°
53°
29
75°
52°
30
75°
54°
1
74°
54°
2
75°
52°
3
73°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Fairfax
Fairfax's September 2026 forecast shows daily high temperatures ranging from 73° to 87°, with overnight lows between 50° and 68°. The average high for September is 77° with an average low of 56°. 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.
