S
M
T
W
T
F
S
30
75°
54°
31
74°
54°
1
76°
58°
2
76°
63°
3
77°
63°
4
83°
64°
5
83°
61°
6
81°
54°
7
76°
53°
8
75°
53°
9
75°
52°
10
73°
52°
11
73°
53°
12
72°
52°
13
76°
58°
14
79°
59°
15
77°
58°
16
71°
55°
17
72°
56°
18
73°
57°
19
74°
49°
20
72°
51°
21
72°
49°
22
75°
47°
23
69°
47°
24
69°
48°
25
70°
53°
26
70°
47°
27
68°
52°
28
69°
52°
29
66°
45°
30
66°
46°
1
67°
52°
2
73°
47°
3
70°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Round Top
Round Top's September 2026 forecast shows daily high temperatures ranging from 66° to 83°, with overnight lows between 45° and 64°. The average high for September is 73° with an average low of 53°. 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 Round Top. See also: October | November | December.
