S
M
T
W
T
F
S
30
68°
44°
31
66°
47°
1
66°
44°
2
67°
44°
3
68°
45°
4
67°
43°
5
65°
44°
6
66°
48°
7
66°
46°
8
65°
48°
9
69°
44°
10
69°
43°
11
67°
42°
12
65°
45°
13
70°
47°
14
71°
50°
15
70°
49°
16
71°
49°
17
72°
50°
18
70°
48°
19
61°
42°
20
58°
38°
21
Hist. Avg.
64°
47°
22
Hist. Avg.
64°
46°
23
Hist. Avg.
63°
46°
24
Hist. Avg.
63°
46°
25
Hist. Avg.
62°
45°
26
Hist. Avg.
62°
45°
27
Hist. Avg.
62°
44°
28
Hist. Avg.
61°
44°
29
Hist. Avg.
61°
44°
30
Hist. Avg.
60°
43°
1
Hist. Avg.
60°
43°
2
Hist. Avg.
60°
42°
3
Hist. Avg.
59°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Knife River
Knife River's September 2026 forecast shows daily high temperatures ranging from 58° to 72°, with overnight lows between 38° and 50°. The average high for September is 67° with an average low of 45°. 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 Knife River. See also: October | November | December.
