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°
62°
15
80°
59°
16
86°
65°
17
88°
69°
18
84°
65°
19
80°
64°
20
85°
66°
21
78°
63°
22
69°
56°
23
75°
57°
24
71°
54°
25
72°
54°
26
73°
55°
27
72°
53°
28
71°
52°
29
75°
57°
30
71°
55°
1
68°
56°
2
72°
56°
3
74°
54°
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 68° to 88°, with overnight lows between 52° and 69°. The average high for September is 76° with an average low of 58°. 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.
