S
M
T
W
T
F
S
30
89°
69°
31
89°
67°
1
84°
68°
2
83°
68°
3
83°
67°
4
84°
68°
5
83°
67°
6
83°
67°
7
85°
66°
8
82°
62°
9
82°
61°
10
83°
63°
11
81°
62°
12
85°
64°
13
85°
66°
14
86°
60°
15
84°
59°
16
79°
58°
17
80°
59°
18
82°
60°
19
84°
58°
20
84°
58°
21
83°
61°
22
83°
63°
23
82°
58°
24
81°
57°
25
82°
56°
26
82°
57°
27
81°
60°
28
82°
60°
29
82°
59°
30
83°
59°
1
81°
58°
2
81°
60°
3
82°
58°
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 79° to 89°, with overnight lows between 56° and 69°. The average high for September is 83° with an average low of 62°. 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.
