S
M
T
W
T
F
S
30
69°
47°
31
70°
48°
1
69°
55°
2
68°
56°
3
67°
55°
4
67°
53°
5
66°
51°
6
68°
47°
7
67°
46°
8
68°
47°
9
68°
45°
10
71°
46°
11
68°
50°
12
64°
45°
13
64°
51°
14
66°
54°
15
Hist. Avg.
69°
49°
16
Hist. Avg.
69°
49°
17
Hist. Avg.
68°
48°
18
Hist. Avg.
68°
48°
19
Hist. Avg.
68°
48°
20
Hist. Avg.
68°
48°
21
Hist. Avg.
67°
48°
22
Hist. Avg.
67°
48°
23
Hist. Avg.
67°
47°
24
Hist. Avg.
66°
47°
25
Hist. Avg.
66°
47°
26
Hist. Avg.
66°
47°
27
Hist. Avg.
66°
47°
28
Hist. Avg.
65°
46°
29
Hist. Avg.
65°
46°
30
Hist. Avg.
65°
46°
1
Hist. Avg.
64°
46°
2
Hist. Avg.
64°
46°
3
Hist. Avg.
64°
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 64° to 71°, with overnight lows between 45° and 56°. The average high for September is 68° with an average low of 50°. 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.
