S
M
T
W
T
F
S
30
79°
55°
31
79°
58°
1
82°
59°
2
84°
59°
3
84°
56°
4
78°
58°
5
79°
55°
6
80°
52°
7
78°
53°
8
79°
54°
9
81°
56°
10
83°
57°
11
84°
57°
12
84°
56°
13
85°
57°
14
84°
54°
15
79°
54°
16
81°
57°
17
84°
57°
18
84°
56°
19
85°
55°
20
85°
57°
21
83°
57°
22
80°
53°
23
77°
51°
24
76°
50°
25
75°
49°
26
76°
51°
27
76°
53°
28
78°
52°
29
82°
49°
30
Hist. Avg.
80°
52°
1
Hist. Avg.
80°
52°
2
Hist. Avg.
80°
52°
3
Hist. Avg.
80°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Fairfax
Fairfax's September 2026 forecast shows daily high temperatures ranging from 75° to 85°, with overnight lows between 49° and 59°. The average high for September is 81° 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.
