S
M
T
W
T
F
S
30
83°
54°
31
80°
51°
1
78°
51°
2
77°
52°
3
77°
52°
4
78°
53°
5
78°
54°
6
75°
58°
7
82°
57°
8
80°
51°
9
75°
50°
10
75°
50°
11
74°
50°
12
75°
50°
13
74°
51°
14
73°
49°
15
74°
54°
16
75°
51°
17
74°
48°
18
75°
49°
19
75°
55°
20
77°
50°
21
78°
49°
22
Hist. Avg.
76°
51°
23
Hist. Avg.
76°
50°
24
Hist. Avg.
75°
50°
25
Hist. Avg.
75°
50°
26
Hist. Avg.
74°
49°
27
Hist. Avg.
74°
49°
28
Hist. Avg.
74°
49°
29
Hist. Avg.
73°
48°
30
Hist. Avg.
73°
48°
1
Hist. Avg.
72°
48°
2
Hist. Avg.
72°
47°
3
Hist. Avg.
72°
47°
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 73° to 83°, with overnight lows between 48° and 58°. The average high for September is 77° with an average low of 52°. 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.
