S
M
T
W
T
F
S
30
103°
72°
31
102°
72°
1
102°
74°
2
102°
75°
3
100°
75°
4
100°
72°
5
103°
72°
6
104°
74°
7
103°
73°
8
103°
77°
9
103°
78°
10
81°
68°
11
92°
66°
12
92°
72°
13
90°
69°
14
96°
74°
15
97°
77°
16
97°
72°
17
97°
73°
18
96°
74°
19
94°
72°
20
88°
71°
21
79°
66°
22
83°
63°
23
84°
61°
24
84°
59°
25
84°
65°
26
76°
67°
27
83°
67°
28
85°
66°
29
81°
64°
30
86°
71°
1
76°
69°
2
75°
59°
3
77°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Delaware
Delaware'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 Delaware. See also: October | November | December.
