S
M
T
W
T
F
S
30
77°
50°
31
72°
49°
1
69°
59°
2
71°
59°
3
71°
55°
4
72°
53°
5
77°
50°
6
77°
51°
7
86°
56°
8
92°
60°
9
97°
62°
10
89°
57°
11
80°
54°
12
85°
55°
13
86°
56°
14
81°
55°
15
82°
54°
16
81°
57°
17
82°
58°
18
81°
57°
19
81°
55°
20
80°
54°
21
75°
56°
22
76°
55°
23
78°
56°
24
78°
55°
25
79°
54°
26
75°
57°
27
81°
57°
28
82°
56°
29
82°
58°
30
81°
58°
1
82°
57°
2
81°
56°
3
82°
57°
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 75° to 97°, with overnight lows between 54° and 62°. The average high for September is 82° 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.
