S
M
T
W
T
F
S
30
94°
64°
31
99°
66°
1
100°
71°
2
100°
74°
3
100°
74°
4
100°
74°
5
103°
74°
6
92°
71°
7
89°
64°
8
94°
60°
9
95°
70°
10
82°
70°
11
87°
68°
12
93°
67°
13
89°
66°
14
87°
61°
15
98°
67°
16
96°
74°
17
98°
73°
18
98°
72°
19
96°
71°
20
94°
69°
21
77°
67°
22
73°
60°
23
71°
58°
24
71°
61°
25
74°
58°
26
71°
56°
27
75°
55°
28
80°
54°
29
83°
63°
30
80°
62°
1
71°
56°
2
75°
57°
3
79°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Petersburg
Petersburg's September 2026 forecast shows daily high temperatures ranging from 71° to 83°, with overnight lows between 54° and 63°. The average high for September is 76° with an average low of 58°. 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 Petersburg. See also: October | November | December.
