S
M
T
W
T
F
S
30
87°
70°
31
86°
69°
1
94°
74°
2
92°
73°
3
92°
70°
4
91°
70°
5
81°
68°
6
83°
61°
7
81°
59°
8
86°
57°
9
89°
66°
10
88°
71°
11
79°
66°
12
80°
66°
13
90°
72°
14
79°
59°
15
77°
52°
16
83°
65°
17
89°
71°
18
84°
65°
19
80°
66°
20
82°
66°
21
71°
60°
22
69°
59°
23
68°
57°
24
69°
58°
25
72°
55°
26
73°
55°
27
75°
54°
28
74°
56°
29
75°
52°
30
71°
55°
1
68°
56°
2
73°
57°
3
66°
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 66° to 89°, with overnight lows between 52° and 71°. The average high for September is 75° with an average low of 59°. 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.
