S
M
T
W
T
F
S
30
68°
52°
31
68°
54°
1
69°
53°
2
67°
52°
3
66°
54°
4
66°
53°
5
65°
51°
6
67°
51°
7
64°
50°
8
64°
53°
9
63°
47°
10
64°
51°
11
62°
49°
12
63°
52°
13
64°
52°
14
65°
53°
15
64°
53°
16
66°
51°
17
64°
51°
18
64°
52°
19
Hist. Avg.
60°
48°
20
Hist. Avg.
60°
48°
21
Hist. Avg.
60°
48°
22
Hist. Avg.
60°
48°
23
Hist. Avg.
59°
48°
24
Hist. Avg.
59°
48°
25
Hist. Avg.
59°
47°
26
Hist. Avg.
59°
47°
27
Hist. Avg.
59°
47°
28
Hist. Avg.
58°
47°
29
Hist. Avg.
58°
47°
30
Hist. Avg.
58°
47°
1
Hist. Avg.
58°
47°
2
Hist. Avg.
58°
46°
3
Hist. Avg.
58°
46°
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 62° to 69°, with overnight lows between 47° and 54°. The average high for September is 65° 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.
