S
M
T
W
T
F
S
30
78°
56°
31
79°
47°
1
72°
47°
2
69°
52°
3
70°
56°
4
76°
49°
5
79°
45°
6
71°
45°
7
69°
46°
8
69°
53°
9
70°
52°
10
69°
51°
11
68°
47°
12
67°
45°
13
67°
42°
14
65°
43°
15
66°
49°
16
65°
53°
17
69°
52°
18
74°
51°
19
74°
49°
20
70°
46°
21
71°
45°
22
66°
42°
23
63°
41°
24
62°
40°
25
63°
41°
26
63°
40°
27
69°
48°
28
72°
48°
29
Hist. Avg.
65°
43°
30
Hist. Avg.
65°
43°
1
Hist. Avg.
64°
43°
2
Hist. Avg.
64°
42°
3
Hist. Avg.
64°
42°
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 62° to 79°, with overnight lows between 40° and 56°. The average high for September is 70° with an average low of 47°. 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.
