S
M
T
W
T
F
S
30
87°
70°
31
86°
69°
1
96°
72°
2
96°
73°
3
98°
73°
4
90°
70°
5
82°
62°
6
80°
61°
7
79°
61°
8
78°
60°
9
83°
63°
10
84°
64°
11
83°
61°
12
79°
60°
13
80°
58°
14
78°
58°
15
74°
62°
16
72°
61°
17
71°
57°
18
71°
53°
19
70°
53°
20
70°
56°
21
74°
57°
22
76°
59°
23
78°
60°
24
78°
59°
25
76°
58°
26
74°
58°
27
75°
59°
28
75°
58°
29
76°
57°
30
71°
55°
1
67°
52°
2
69°
55°
3
72°
56°
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 67° to 98°, with overnight lows between 52° and 73°. The average high for September is 78° with an average low of 60°. 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.
