S
M
T
W
T
F
S
26
45°
36°
27
45°
36°
28
51°
35°
29
43°
32°
30
43°
26°
1
49°
25°
2
57°
20°
3
65°
32°
4
58°
33°
5
42°
32°
6
44°
32°
7
49°
26°
8
60°
21°
9
52°
30°
10
47°
30°
11
49°
33°
12
38°
33°
13
66°
33°
14
62°
27°
15
83°
41°
16
69°
38°
17
54°
30°
18
N/A
19
46°
34°
20
45°
36°
21
52°
39°
22
50°
38°
23
56°
42°
24
62°
44°
25
64°
45°
26
68°
47°
27
69°
48°
28
70°
49°
29
69°
48°
30
69°
49°
31
68°
50°
1
69°
42°
2
60°
47°
3
61°
47°
4
61°
46°
5
65°
47°
6
60°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Grand Portage Ut
Grand Portage Ut's May 2026 forecast shows daily high temperatures ranging from 45° to 70°, with overnight lows between 34° and 50°. The average high for May is 61° with an average low of 44°. 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 Grand Portage Ut. See also: June | July | August.