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
N/A
9
91°
77°
10
91°
77°
11
92°
79°
12
94°
81°
13
94°
79°
14
93°
79°
15
94°
75°
16
92°
74°
17
91°
74°
18
90°
72°
19
91°
71°
20
89°
70°
21
88°
69°
22
90°
71°
23
88°
75°
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
*Temporarily Unavailable
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 81°. The average high for September is 89° with an average low of 74°. 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.
