S
M
T
W
T
F
S
30
76°
60°
31
66°
60°
1
78°
65°
2
69°
64°
3
79°
64°
4
74°
57°
5
71°
54°
6
70°
52°
7
73°
54°
8
73°
58°
9
71°
63°
10
72°
56°
11
67°
54°
12
67°
53°
13
71°
56°
14
74°
59°
15
74°
58°
16
73°
41°
17
71°
48°
18
64°
46°
19
70°
47°
20
72°
54°
21
72°
54°
22
71°
53°
23
70°
50°
24
65°
47°
25
68°
50°
26
70°
53°
27
67°
52°
28
60°
47°
29
59°
45°
30
60°
43°
1
58°
41°
2
58°
45°
3
57°
40°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Johnson City
Johnson City's September 2026 forecast shows daily high temperatures ranging from 57° to 74°, with overnight lows between 40° and 63°. The average high for September is 68° with an average low of 51°. 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 Johnson City. See also: October | November | December.
