S
M
T
W
T
F
S
30
77°
58°
31
72°
55°
1
71°
56°
2
71°
54°
3
72°
59°
4
74°
62°
5
79°
62°
6
78°
63°
7
76°
58°
8
78°
58°
9
73°
61°
10
77°
54°
11
79°
57°
12
74°
61°
13
77°
57°
14
78°
49°
15
74°
46°
16
64°
46°
17
65°
49°
18
67°
55°
19
68°
57°
20
70°
58°
21
70°
56°
22
74°
56°
23
73°
57°
24
74°
57°
25
75°
56°
26
75°
58°
27
73°
44°
28
73°
42°
29
61°
46°
30
60°
44°
1
59°
45°
2
60°
46°
3
60°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Grimsby
Grimsby's September 2026 forecast shows daily high temperatures ranging from 59° to 79°, with overnight lows between 42° and 63°. The average high for September is 71° 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 Grimsby. See also: October | November | December.
