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
89°
44°
16
84°
44°
17
78°
52°
18
55°
46°
19
57°
39°
20
61°
31°
21
69°
45°
22
65°
49°
23
74°
50°
24
83°
57°
25
86°
63°
26
88°
59°
27
85°
62°
28
85°
58°
29
82°
59°
30
77°
55°
31
75°
56°
1
79°
56°
2
82°
57°
3
82°
58°
4
84°
60°
5
87°
64°
6
79°
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 74° to 88°, with overnight lows between 50° and 64°. The average high for May is 82° with an average low of 58°. 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.
