S
M
T
W
T
F
S
30
93°
69°
31
93°
71°
1
95°
70°
2
98°
71°
3
97°
73°
4
96°
72°
5
95°
68°
6
90°
69°
7
89°
68°
8
91°
67°
9
91°
65°
10
90°
65°
11
89°
60°
12
85°
64°
13
87°
63°
14
85°
64°
15
83°
63°
16
78°
63°
17
78°
62°
18
81°
62°
19
82°
61°
20
81°
62°
21
81°
59°
22
82°
56°
23
82°
56°
24
84°
61°
25
84°
60°
26
81°
61°
27
78°
60°
28
78°
60°
29
82°
59°
30
82°
58°
1
81°
57°
2
80°
57°
3
81°
56°
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 78° to 98°, with overnight lows between 56° and 73°. The average high for September is 85° with an average low of 63°. 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.
