S
M
T
W
T
F
S
30
84°
63°
31
82°
56°
1
79°
55°
2
76°
57°
3
77°
56°
4
77°
56°
5
76°
57°
6
75°
55°
7
75°
55°
8
76°
58°
9
75°
55°
10
74°
55°
11
75°
56°
12
74°
54°
13
75°
55°
14
74°
54°
15
73°
56°
16
74°
52°
17
73°
53°
18
72°
53°
19
75°
52°
20
Hist. Avg.
74°
54°
21
Hist. Avg.
74°
54°
22
Hist. Avg.
73°
53°
23
Hist. Avg.
73°
53°
24
Hist. Avg.
73°
52°
25
Hist. Avg.
72°
52°
26
Hist. Avg.
72°
52°
27
Hist. Avg.
71°
51°
28
Hist. Avg.
71°
51°
29
Hist. Avg.
71°
50°
30
Hist. Avg.
70°
50°
1
Hist. Avg.
70°
50°
2
Hist. Avg.
69°
49°
3
Hist. Avg.
69°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Johnstown
Johnstown's September 2026 forecast shows daily high temperatures ranging from 72° to 84°, with overnight lows between 52° and 63°. The average high for September is 76° 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 Johnstown. See also: October | November | December.
