S
M
T
W
T
F
S
26
67°
35°
27
58°
49°
28
57°
49°
29
64°
43°
30
71°
42°
1
70°
45°
2
73°
50°
3
76°
45°
4
76°
47°
5
62°
53°
6
58°
52°
7
63°
52°
8
58°
47°
9
67°
47°
10
64°
51°
11
68°
49°
12
77°
44°
13
60°
53°
14
59°
49°
15
53°
45°
16
57°
43°
17
63°
43°
18
63°
49°
19
63°
53°
20
65°
49°
21
71°
45°
22
73°
50°
23
62°
51°
24
67°
49°
25
62°
51°
26
63°
50°
27
69°
46°
28
74°
55°
29
61°
50°
30
62°
46°
31
66°
45°
1
74°
54°
2
79°
53°
3
66°
54°
4
64°
49°
5
65°
48°
6
62°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in South Bellingham
South Bellingham's May 2026 forecast shows daily high temperatures ranging from 62° to 79°, with overnight lows between 45° and 54°. The average high for May is 67° 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 May weather will actually feel in South Bellingham. See also: June | July | August.