S
M
T
W
T
F
S
30
77°
54°
31
78°
56°
1
78°
57°
2
79°
58°
3
77°
58°
4
77°
57°
5
76°
57°
6
75°
56°
7
75°
57°
8
74°
56°
9
75°
55°
10
75°
55°
11
76°
53°
12
76°
55°
13
75°
56°
14
76°
56°
15
74°
55°
16
73°
54°
17
71°
55°
18
69°
51°
19
70°
43°
20
64°
52°
21
64°
49°
22
65°
44°
23
63°
43°
24
62°
45°
25
65°
52°
26
69°
51°
27
62°
44°
28
62°
43°
29
61°
44°
30
61°
49°
1
62°
51°
2
60°
44°
3
61°
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 60° to 79°, with overnight lows between 40° and 58°. The average high for September is 70° with an average low of 52°. 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.
