S
M
T
W
T
F
S
30
78°
60°
31
80°
63°
1
83°
64°
2
83°
64°
3
82°
61°
4
81°
64°
5
82°
62°
6
78°
63°
7
76°
61°
8
76°
62°
9
81°
57°
10
79°
56°
11
75°
62°
12
80°
61°
13
80°
62°
14
75°
60°
15
81°
61°
16
73°
59°
17
78°
54°
18
73°
59°
19
Hist. Avg.
78°
57°
20
Hist. Avg.
78°
56°
21
Hist. Avg.
77°
56°
22
Hist. Avg.
77°
56°
23
Hist. Avg.
77°
55°
24
Hist. Avg.
76°
55°
25
Hist. Avg.
76°
54°
26
Hist. Avg.
75°
54°
27
Hist. Avg.
75°
53°
28
Hist. Avg.
75°
53°
29
Hist. Avg.
74°
52°
30
Hist. Avg.
74°
52°
1
Hist. Avg.
73°
52°
2
Hist. Avg.
73°
51°
3
Hist. Avg.
73°
51°
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 54° and 64°. The average high for September is 79° with an average low of 61°. 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.
