S
M
T
W
T
F
S
30
77°
38°
31
78°
40°
1
79°
42°
2
85°
47°
3
84°
45°
4
75°
43°
5
76°
40°
6
77°
43°
7
75°
42°
8
76°
43°
9
78°
42°
10
80°
42°
11
78°
45°
12
80°
45°
13
83°
40°
14
81°
34°
15
73°
35°
16
73°
36°
17
74°
38°
18
75°
42°
19
82°
41°
20
82°
40°
21
81°
34°
22
78°
32°
23
70°
33°
24
68°
32°
25
69°
30°
26
68°
32°
27
68°
36°
28
71°
38°
29
75°
34°
30
76°
31°
1
Hist. Avg.
72°
34°
2
Hist. Avg.
71°
34°
3
Hist. Avg.
71°
34°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Klamath Falls
Klamath Falls's September 2026 forecast shows daily high temperatures ranging from 68° to 85°, with overnight lows between 30° and 47°. The average high for September is 76° with an average low of 39°. 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 Klamath Falls. See also: October | November | December.
