S
M
T
W
T
F
S
26
59°
34°
27
61°
33°
28
65°
36°
29
68°
48°
30
70°
43°
1
74°
48°
2
80°
52°
3
81°
49°
4
81°
49°
5
79°
50°
6
78°
47°
7
78°
51°
8
77°
49°
9
77°
53°
10
91°
56°
11
84°
59°
12
96°
68°
13
82°
54°
14
81°
54°
15
75°
51°
16
72°
47°
17
74°
51°
18
79°
54°
19
77°
54°
20
75°
51°
21
77°
54°
22
74°
48°
23
76°
52°
24
79°
54°
25
79°
52°
26
77°
46°
27
64°
44°
28
67°
44°
29
69°
48°
30
72°
55°
31
71°
51°
1
72°
50°
2
73°
49°
3
78°
52°
4
83°
57°
5
82°
58°
6
83°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Boise
Boise's May 2026 forecast shows daily high temperatures ranging from 64° to 96°, with overnight lows between 44° and 68°. The average high for May is 77° with an average low of 53°. 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 Boise. See also: June | July | August.
