S
M
T
W
T
F
S
30
90°
64°
31
92°
63°
1
93°
64°
2
92°
65°
3
93°
68°
4
95°
65°
5
94°
65°
6
93°
66°
7
94°
67°
8
94°
65°
9
93°
66°
10
90°
65°
11
86°
66°
12
86°
67°
13
90°
66°
14
88°
66°
15
89°
65°
16
91°
66°
17
91°
65°
18
92°
65°
19
90°
64°
20
91°
65°
21
90°
64°
22
91°
65°
23
90°
64°
24
89°
64°
25
83°
63°
26
83°
63°
27
86°
62°
28
88°
57°
29
82°
58°
30
83°
56°
1
86°
53°
2
79°
52°
3
79°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Rio Frio
Rio Frio's September 2026 forecast shows daily high temperatures ranging from 79° to 95°, with overnight lows between 52° and 68°. The average high for September is 89° with an average low of 63°. 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 Rio Frio. See also: October | November | December.
