S
M
T
W
T
F
S
30
63°
55°
31
66°
52°
1
64°
54°
2
63°
54°
3
66°
57°
4
64°
55°
5
64°
50°
6
67°
54°
7
63°
50°
8
60°
45°
9
62°
47°
10
62°
52°
11
63°
49°
12
61°
54°
13
64°
53°
14
63°
51°
15
62°
47°
16
61°
49°
17
61°
50°
18
62°
51°
19
60°
51°
20
62°
50°
21
62°
51°
22
61°
51°
23
62°
50°
24
63°
47°
25
59°
44°
26
59°
44°
27
60°
48°
28
61°
49°
29
60°
48°
30
60°
46°
1
59°
49°
2
60°
49°
3
60°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Grangemouth
Grangemouth's September 2026 forecast shows daily high temperatures ranging from 59° to 67°, with overnight lows between 44° and 54°. The average high for September is 61° with an average low of 49°. 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 Grangemouth. See also: October | November | December.
