S
M
T
W
T
F
S
30
103°
80°
31
99°
78°
1
100°
79°
2
97°
77°
3
99°
76°
4
98°
75°
5
96°
74°
6
96°
74°
7
97°
76°
8
100°
77°
9
101°
75°
10
88°
66°
11
85°
65°
12
87°
67°
13
89°
70°
14
89°
69°
15
88°
70°
16
89°
70°
17
83°
69°
18
81°
69°
19
83°
68°
20
85°
69°
21
87°
69°
22
88°
68°
23
87°
67°
24
88°
68°
25
88°
67°
26
87°
66°
27
87°
66°
28
85°
65°
29
78°
66°
30
82°
66°
1
84°
65°
2
85°
65°
3
85°
64°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Prosper
Prosper's September 2026 forecast shows daily high temperatures ranging from 78° to 103°, with overnight lows between 64° and 80°. The average high for September is 90° with an average low of 70°. 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 Prosper. See also: October | November | December.
