S
M
T
W
T
F
S
30
77°
56°
31
77°
60°
1
75°
60°
2
72°
63°
3
79°
62°
4
83°
59°
5
77°
56°
6
71°
54°
7
76°
55°
8
73°
52°
9
72°
53°
10
74°
56°
11
76°
57°
12
76°
54°
13
74°
52°
14
73°
50°
15
70°
49°
16
69°
54°
17
73°
49°
18
68°
46°
19
68°
45°
20
69°
49°
21
73°
53°
22
76°
54°
23
76°
53°
24
75°
50°
25
74°
50°
26
74°
51°
27
75°
52°
28
74°
51°
29
73°
46°
30
65°
42°
1
63°
42°
2
65°
48°
3
71°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Waterbury
Waterbury's September 2026 forecast shows daily high temperatures ranging from 63° to 83°, with overnight lows between 42° and 63°. The average high for September is 73° with an average low of 52°. 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 Waterbury. See also: October | November | December.
