S
M
T
W
T
F
S
30
79°
56°
31
75°
64°
1
70°
62°
2
73°
61°
3
79°
67°
4
83°
68°
5
78°
61°
6
70°
56°
7
79°
50°
8
80°
55°
9
77°
58°
10
81°
66°
11
76°
54°
12
73°
51°
13
75°
67°
14
75°
50°
15
68°
49°
16
N/A
17
77°
66°
18
81°
49°
19
69°
56°
20
66°
57°
21
67°
56°
22
64°
57°
23
66°
56°
24
68°
55°
25
70°
57°
26
69°
56°
27
70°
55°
28
72°
56°
29
71°
55°
30
70°
54°
1
64°
54°
2
72°
56°
3
65°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Mystic
Mystic's September 2026 forecast shows daily high temperatures ranging from 64° to 81°, with overnight lows between 49° and 66°. The average high for September is 69° with an average low of 56°. 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 Mystic. See also: October | November | December.
