S
M
T
W
T
F
S
30
93°
77°
31
95°
76°
1
96°
78°
2
98°
81°
3
97°
82°
4
96°
78°
5
94°
78°
6
96°
76°
7
97°
76°
8
95°
77°
9
93°
78°
10
90°
79°
11
92°
82°
12
94°
79°
13
92°
79°
14
93°
79°
15
94°
78°
16
92°
76°
17
93°
74°
18
94°
73°
19
91°
72°
20
92°
72°
21
91°
72°
22
92°
70°
23
88°
69°
24
85°
75°
25
90°
75°
26
87°
74°
27
84°
74°
28
84°
73°
29
87°
74°
30
89°
74°
1
88°
73°
2
85°
73°
3
84°
72°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Port Lavaca
Port Lavaca's September 2026 forecast shows daily high temperatures ranging from 84° to 94°, with overnight lows between 69° and 82°. The average high for September is 90° with an average low of 75°. 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 Port Lavaca. See also: October | November | December.
