S
M
T
W
T
F
S
30
75°
54°
31
77°
47°
1
80°
47°
2
72°
46°
3
69°
46°
4
69°
47°
5
70°
48°
6
73°
57°
7
78°
53°
8
80°
45°
9
75°
47°
10
71°
45°
11
71°
56°
12
73°
45°
13
75°
41°
14
68°
45°
15
69°
53°
16
72°
50°
17
76°
42°
18
67°
43°
19
67°
43°
20
73°
47°
21
66°
51°
22
66°
53°
23
76°
50°
24
75°
49°
25
72°
51°
26
74°
51°
27
73°
50°
28
74°
50°
29
72°
49°
30
74°
49°
1
74°
38°
2
73°
36°
3
59°
37°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sioux Falls Junction
Sioux Falls Junction's September 2026 forecast shows daily high temperatures ranging from 59° to 80°, with overnight lows between 36° and 57°. The average high for September is 72° with an average low of 47°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Sioux Falls Junction. See also: October | November | December.
