S
M
T
W
T
F
S
30
77°
56°
31
79°
55°
1
80°
54°
2
76°
53°
3
75°
58°
4
80°
61°
5
82°
60°
6
82°
53°
7
76°
52°
8
75°
52°
9
78°
59°
10
75°
58°
11
77°
59°
12
74°
57°
13
75°
52°
14
73°
49°
15
71°
49°
16
72°
50°
17
72°
55°
18
76°
56°
19
79°
57°
20
80°
56°
21
75°
52°
22
77°
55°
23
72°
48°
24
78°
46°
25
69°
45°
26
68°
50°
27
69°
46°
28
Hist. Avg.
72°
49°
29
Hist. Avg.
71°
48°
30
Hist. Avg.
71°
48°
1
Hist. Avg.
70°
48°
2
Hist. Avg.
70°
47°
3
Hist. Avg.
70°
47°
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 68° to 82°, with overnight lows between 45° and 61°. The average high for September is 76° 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.
