S
M
T
W
T
F
S
30
81°
62°
31
88°
71°
1
89°
73°
2
93°
71°
3
N/A
4
89°
69°
5
84°
57°
6
81°
56°
7
82°
61°
8
84°
65°
9
89°
66°
10
81°
57°
11
76°
55°
12
79°
56°
13
78°
53°
14
77°
54°
15
78°
54°
16
80°
55°
17
82°
52°
18
76°
57°
19
81°
58°
20
79°
58°
21
77°
57°
22
78°
55°
23
75°
51°
24
71°
54°
25
77°
55°
26
75°
52°
27
68°
47°
28
66°
44°
29
66°
45°
30
66°
44°
1
65°
42°
2
66°
52°
3
71°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Delaware
Delaware's September 2026 forecast shows daily high temperatures ranging from 65° to 89°, with overnight lows between 42° and 69°. The average high for September is 77° with an average low of 54°. 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.
