S
M
T
W
T
F
S
30
89°
68°
31
90°
70°
1
96°
72°
2
96°
73°
3
91°
69°
4
87°
65°
5
83°
64°
6
86°
65°
7
83°
64°
8
86°
65°
9
84°
62°
10
83°
64°
11
77°
59°
12
78°
60°
13
77°
60°
14
80°
61°
15
83°
63°
16
84°
65°
17
84°
65°
18
85°
64°
19
84°
65°
20
84°
65°
21
83°
64°
22
84°
64°
23
83°
63°
24
84°
62°
25
80°
60°
26
77°
59°
27
77°
58°
28
76°
58°
29
79°
59°
30
80°
59°
1
80°
58°
2
79°
59°
3
81°
60°
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 76° to 96°, with overnight lows between 58° and 73°. The average high for September is 83° with an average low of 63°. 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.
