S
M
T
W
T
F
S
30
84°
65°
31
84°
69°
1
93°
73°
2
87°
70°
3
89°
70°
4
87°
69°
5
82°
62°
6
81°
58°
7
81°
55°
8
86°
54°
9
89°
61°
10
87°
71°
11
82°
63°
12
79°
62°
13
87°
71°
14
77°
52°
15
78°
47°
16
86°
55°
17
85°
65°
18
84°
62°
19
77°
62°
20
81°
68°
21
70°
61°
22
61°
57°
23
65°
50°
24
67°
45°
25
75°
44°
26
70°
57°
27
65°
61°
28
69°
60°
29
75°
56°
30
79°
58°
1
87°
57°
2
90°
58°
3
71°
56°
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 ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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.
