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°
52°
4
66°
37°
5
57°
32°
6
57°
37°
7
68°
38°
8
70°
41°
9
74°
48°
10
69°
47°
11
74°
50°
12
81°
52°
13
80°
52°
14
79°
50°
15
76°
53°
16
82°
59°
17
74°
53°
18
74°
54°
19
71°
54°
20
69°
48°
21
66°
46°
22
66°
46°
23
67°
47°
24
68°
47°
25
67°
48°
26
68°
48°
27
68°
49°
28
69°
50°
29
72°
58°
30
71°
53°
31
70°
52°
1
76°
58°
2
79°
60°
3
81°
61°
4
82°
62°
5
82°
63°
6
81°
63°
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 57° to 82°, with overnight lows between 32° and 63°. The average high for May is 72° with an average low of 51°. 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.
