S
M
T
W
T
F
S
30
86°
57°
31
81°
54°
1
80°
55°
2
79°
57°
3
80°
59°
4
82°
58°
5
86°
57°
6
78°
58°
7
79°
53°
8
78°
54°
9
78°
53°
10
79°
51°
11
78°
51°
12
77°
52°
13
76°
51°
14
75°
55°
15
77°
56°
16
80°
52°
17
81°
53°
18
82°
52°
19
79°
50°
20
77°
49°
21
Hist. Avg.
78°
54°
22
Hist. Avg.
77°
53°
23
Hist. Avg.
77°
53°
24
Hist. Avg.
77°
53°
25
Hist. Avg.
76°
53°
26
Hist. Avg.
76°
52°
27
Hist. Avg.
76°
52°
28
Hist. Avg.
75°
52°
29
Hist. Avg.
75°
51°
30
Hist. Avg.
75°
51°
1
Hist. Avg.
74°
51°
2
Hist. Avg.
74°
50°
3
Hist. Avg.
74°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in New Haven
New Haven's September 2026 forecast shows daily high temperatures ranging from 75° to 86°, with overnight lows between 49° and 59°. The average high for September is 79° 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 New Haven. See also: October | November | December.
