S
M
T
W
T
F
S
26
55°
40°
27
52°
41°
28
54°
33°
29
57°
33°
30
55°
35°
1
55°
31°
2
68°
30°
3
72°
49°
4
64°
38°
5
54°
33°
6
56°
25°
7
65°
33°
8
77°
38°
9
64°
39°
10
68°
33°
11
79°
36°
12
75°
51°
13
78°
40°
14
81°
51°
15
87°
49°
16
83°
58°
17
81°
53°
18
60°
43°
19
59°
40°
20
70°
51°
21
72°
53°
22
80°
60°
23
78°
57°
24
80°
59°
25
76°
58°
26
79°
61°
27
81°
60°
28
84°
65°
29
68°
53°
30
70°
52°
31
71°
53°
1
70°
53°
2
72°
60°
3
73°
62°
4
81°
64°
5
82°
63°
6
80°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Sioux Falls
Sioux Falls's May 2026 forecast shows daily high temperatures ranging from 59° to 87°, with overnight lows between 40° and 65°. The average high for May is 76° with an average low of 56°. 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 Sioux Falls. See also: June | July | August.
