S
M
T
W
T
F
S
30
82°
64°
31
87°
68°
1
90°
73°
2
92°
71°
3
93°
72°
4
88°
70°
5
83°
68°
6
77°
60°
7
79°
58°
8
84°
57°
9
83°
66°
10
78°
63°
11
78°
54°
12
80°
63°
13
81°
54°
14
71°
46°
15
90°
57°
16
82°
70°
17
82°
71°
18
74°
62°
19
70°
62°
20
76°
58°
21
65°
56°
22
62°
52°
23
61°
57°
24
66°
50°
25
69°
45°
26
72°
45°
27
74°
43°
28
74°
48°
29
77°
47°
30
74°
53°
1
87°
65°
2
69°
50°
3
67°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in New Haven
New Haven'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 New Haven. See also: October | November | December.
