S
M
T
W
T
F
S
30
73°
49°
31
84°
45°
1
86°
62°
2
76°
58°
3
76°
47°
4
66°
45°
5
78°
44°
6
77°
52°
7
68°
46°
8
73°
41°
9
80°
47°
10
83°
58°
11
79°
57°
12
85°
53°
13
69°
44°
14
65°
41°
15
73°
47°
16
78°
52°
17
81°
49°
18
75°
49°
19
77°
49°
20
81°
53°
21
79°
52°
22
78°
53°
23
80°
52°
24
75°
49°
25
73°
49°
26
86°
54°
27
72°
46°
28
65°
40°
29
63°
40°
30
66°
45°
1
66°
43°
2
74°
46°
3
63°
37°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Twin Falls
Twin Falls's September 2026 forecast shows daily high temperatures ranging from 63° to 86°, with overnight lows between 37° and 54°. The average high for September is 73° 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 Twin Falls. See also: October | November | December.
