S
M
T
W
T
F
S
30
80°
55°
31
79°
56°
1
78°
61°
2
77°
63°
3
85°
62°
4
86°
63°
5
85°
58°
6
80°
54°
7
78°
58°
8
81°
53°
9
77°
52°
10
76°
52°
11
76°
53°
12
78°
52°
13
77°
58°
14
82°
56°
15
75°
51°
16
74°
55°
17
73°
53°
18
72°
56°
19
77°
49°
20
74°
51°
21
75°
49°
22
78°
49°
23
73°
48°
24
72°
48°
25
72°
52°
26
74°
54°
27
73°
54°
28
76°
53°
29
77°
46°
30
69°
48°
1
70°
54°
2
76°
52°
3
75°
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 69° to 86°, with overnight lows between 45° and 63°. The average high for September is 77° with an average low of 54°. 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.
