S
M
T
W
T
F
S
30
81°
63°
31
71°
63°
1
68°
62°
2
73°
63°
3
76°
61°
4
79°
63°
5
72°
58°
6
68°
55°
7
75°
57°
8
76°
61°
9
76°
61°
10
80°
69°
11
74°
59°
12
72°
54°
13
70°
62°
14
71°
60°
15
65°
51°
16
71°
50°
17
76°
64°
18
75°
60°
19
64°
51°
20
63°
53°
21
65°
59°
22
65°
58°
23
64°
57°
24
63°
58°
25
62°
57°
26
61°
59°
27
68°
61°
28
67°
57°
29
65°
58°
30
69°
58°
1
73°
60°
2
72°
60°
3
66°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Harwich
Harwich's September 2026 forecast shows daily high temperatures ranging from 61° to 73°, with overnight lows between 57° and 61°. The average high for September is 67° with an average low of 59°. 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 Harwich. See also: October | November | December.
