S
M
T
W
T
F
S
30
91°
68°
31
92°
68°
1
88°
67°
2
92°
67°
3
91°
62°
4
90°
60°
5
83°
60°
6
84°
64°
7
88°
64°
8
90°
66°
9
89°
67°
10
90°
66°
11
88°
65°
12
87°
64°
13
87°
62°
14
88°
63°
15
89°
65°
16
79°
61°
17
80°
63°
18
Hist. Avg.
83°
59°
19
Hist. Avg.
82°
58°
20
Hist. Avg.
82°
58°
21
Hist. Avg.
82°
57°
22
Hist. Avg.
81°
57°
23
Hist. Avg.
81°
57°
24
Hist. Avg.
81°
56°
25
Hist. Avg.
80°
56°
26
Hist. Avg.
80°
55°
27
Hist. Avg.
79°
55°
28
Hist. Avg.
79°
55°
29
Hist. Avg.
79°
54°
30
Hist. Avg.
78°
54°
1
Hist. Avg.
78°
53°
2
Hist. Avg.
78°
53°
3
Hist. Avg.
77°
53°
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 79° to 92°, with overnight lows between 60° and 68°. The average high for September is 88° with an average low of 64°. 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.
