S
M
T
W
T
F
S
30
81°
61°
31
80°
60°
1
80°
61°
2
81°
63°
3
79°
66°
4
80°
60°
5
82°
61°
6
81°
60°
7
80°
59°
8
79°
58°
9
79°
60°
10
78°
60°
11
79°
58°
12
78°
57°
13
78°
57°
14
79°
58°
15
80°
63°
16
82°
62°
17
80°
56°
18
76°
54°
19
76°
56°
20
77°
59°
21
76°
55°
22
75°
56°
23
79°
58°
24
80°
59°
25
81°
60°
26
80°
52°
27
79°
52°
28
73°
51°
29
73°
50°
30
72°
50°
1
Hist. Avg.
75°
53°
2
Hist. Avg.
74°
53°
3
Hist. Avg.
74°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Frederick
Frederick's September 2026 forecast shows daily high temperatures ranging from 72° to 82°, with overnight lows between 50° and 66°. The average high for September is 79° 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 Frederick. See also: October | November | December.
