S
M
T
W
T
F
S
30
81°
60°
31
87°
64°
1
87°
64°
2
84°
63°
3
86°
56°
4
80°
55°
5
79°
56°
6
82°
63°
7
85°
62°
8
85°
62°
9
79°
61°
10
80°
62°
11
84°
61°
12
85°
61°
13
84°
60°
14
84°
61°
15
83°
60°
16
83°
60°
17
82°
55°
18
81°
51°
19
74°
49°
20
75°
49°
21
73°
48°
22
73°
50°
23
74°
50°
24
77°
49°
25
74°
55°
26
78°
56°
27
76°
55°
28
78°
55°
29
77°
54°
30
78°
53°
1
75°
52°
2
77°
54°
3
70°
48°
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 70° to 87°, with overnight lows between 48° and 64°. The average high for September is 80° 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.
