S
M
T
W
T
F
S
30
85°
65°
31
82°
67°
1
88°
71°
2
92°
71°
3
88°
66°
4
81°
67°
5
79°
64°
6
80°
59°
7
80°
59°
8
83°
66°
9
87°
69°
10
77°
58°
11
74°
60°
12
79°
66°
13
82°
63°
14
77°
60°
15
77°
57°
16
74°
58°
17
75°
60°
18
73°
57°
19
70°
54°
20
78°
59°
21
77°
59°
22
73°
58°
23
72°
58°
24
76°
57°
25
76°
58°
26
75°
58°
27
75°
57°
28
76°
58°
29
76°
58°
30
75°
57°
1
76°
57°
2
74°
52°
3
72°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Upper St. Clair
Upper St. Clair's September 2026 forecast shows daily high temperatures ranging from 70° to 87°, with overnight lows between 46° and 69°. The average high for September is 76° 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 Upper St. Clair. See also: October | November | December.
