S
M
T
W
T
F
S
30
68°
55°
31
64°
57°
1
66°
57°
2
N/A
3
65°
53°
4
65°
50°
5
63°
57°
6
68°
53°
7
64°
50°
8
60°
50°
9
61°
49°
10
62°
53°
11
63°
53°
12
62°
50°
13
63°
51°
14
64°
53°
15
63°
53°
16
61°
53°
17
62°
52°
18
64°
54°
19
64°
53°
20
63°
53°
21
64°
54°
22
64°
52°
23
62°
52°
24
63°
53°
25
63°
52°
26
62°
52°
27
63°
51°
28
63°
52°
29
62°
52°
30
62°
50°
1
58°
49°
2
58°
51°
3
59°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Belfast
Belfast's September 2026 forecast shows daily high temperatures ranging from 58° to 68°, with overnight lows between 49° and 57°. The average high for September is 63° 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 Belfast. See also: October | November | December.
