S
M
T
W
T
F
S
30
78°
56°
31
80°
55°
1
83°
61°
2
82°
63°
3
84°
63°
4
81°
54°
5
82°
61°
6
82°
61°
7
80°
60°
8
83°
61°
9
84°
62°
10
85°
61°
11
84°
61°
12
83°
60°
13
82°
61°
14
80°
60°
15
80°
60°
16
78°
59°
17
77°
57°
18
78°
53°
19
75°
49°
20
72°
50°
21
71°
52°
22
73°
47°
23
70°
51°
24
70°
56°
25
69°
55°
26
75°
54°
27
70°
56°
28
72°
55°
29
73°
54°
30
71°
44°
1
72°
42°
2
65°
41°
3
63°
40°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Knoxville
Knoxville's September 2026 forecast shows daily high temperatures ranging from 63° to 85°, with overnight lows between 40° and 63°. The average high for September is 77° with an average low of 55°. 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 Knoxville. See also: October | November | December.
