S
M
T
W
T
F
S
30
85°
68°
31
85°
68°
1
87°
66°
2
79°
61°
3
78°
62°
4
78°
62°
5
79°
60°
6
81°
65°
7
85°
67°
8
85°
66°
9
84°
66°
10
85°
67°
11
85°
66°
12
86°
67°
13
85°
67°
14
85°
60°
15
77°
57°
16
75°
57°
17
76°
56°
18
83°
62°
19
85°
63°
20
84°
63°
21
83°
57°
22
81°
53°
23
72°
56°
24
71°
60°
25
71°
59°
26
78°
59°
27
80°
60°
28
80°
59°
29
78°
59°
30
76°
58°
1
75°
57°
2
78°
52°
3
73°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Adelphi
Adelphi's September 2026 forecast shows daily high temperatures ranging from 71° to 87°, with overnight lows between 47° and 68°. The average high for September is 80° with an average low of 61°. 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 Adelphi. See also: October | November | December.
