S
M
T
W
T
F
S
30
86°
65°
31
88°
68°
1
80°
60°
2
77°
61°
3
79°
59°
4
80°
59°
5
79°
60°
6
75°
54°
7
79°
62°
8
80°
63°
9
81°
61°
10
78°
59°
11
76°
55°
12
76°
56°
13
78°
54°
14
81°
57°
15
82°
61°
16
83°
60°
17
81°
60°
18
82°
61°
19
79°
61°
20
81°
60°
21
81°
60°
22
80°
59°
23
81°
59°
24
80°
57°
25
74°
53°
26
75°
56°
27
78°
56°
28
78°
55°
29
77°
56°
30
78°
56°
1
78°
55°
2
77°
56°
3
78°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Pittsburgh
Pittsburgh's September 2026 forecast shows daily high temperatures ranging from 74° to 88°, with overnight lows between 53° and 68°. The average high for September is 79° with an average low of 59°. 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 Pittsburgh. See also: October | November | December.