S
M
T
W
T
F
S
30
88°
58°
31
80°
60°
1
81°
65°
2
85°
57°
3
86°
63°
4
86°
65°
5
88°
60°
6
87°
56°
7
78°
55°
8
78°
55°
9
79°
59°
10
83°
61°
11
84°
54°
12
78°
55°
13
77°
54°
14
78°
60°
15
83°
56°
16
85°
52°
17
77°
51°
18
74°
51°
19
74°
52°
20
75°
52°
21
72°
51°
22
72°
51°
23
73°
52°
24
73°
55°
25
79°
56°
26
79°
56°
27
80°
48°
28
75°
55°
29
74°
56°
30
78°
54°
1
71°
53°
2
73°
49°
3
69°
46°
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 69° to 88°, with overnight lows between 46° and 65°. The average high for September is 79° with an average low of 55°. 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.
