S
M
T
W
T
F
S
30
93°
67°
31
92°
67°
1
91°
66°
2
93°
67°
3
92°
61°
4
92°
59°
5
84°
59°
6
85°
64°
7
90°
63°
8
91°
66°
9
89°
66°
10
90°
67°
11
89°
65°
12
90°
64°
13
89°
62°
14
90°
64°
15
91°
65°
16
90°
65°
17
Hist. Avg.
84°
61°
18
Hist. Avg.
84°
60°
19
Hist. Avg.
83°
60°
20
Hist. Avg.
83°
59°
21
Hist. Avg.
82°
59°
22
Hist. Avg.
82°
58°
23
Hist. Avg.
82°
58°
24
Hist. Avg.
81°
58°
25
Hist. Avg.
81°
57°
26
Hist. Avg.
80°
57°
27
Hist. Avg.
80°
56°
28
Hist. Avg.
80°
56°
29
Hist. Avg.
79°
56°
30
Hist. Avg.
79°
55°
1
Hist. Avg.
78°
55°
2
Hist. Avg.
78°
54°
3
Hist. Avg.
78°
54°
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 84° to 93°, with overnight lows between 59° and 67°. The average high for September is 90° with an average low of 64°. 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.
