S
M
T
W
T
F
S
26
89°
79°
27
89°
79°
28
90°
78°
29
92°
78°
30
93°
79°
31
93°
79°
1
92°
78°
2
92°
80°
3
92°
80°
4
93°
79°
5
94°
80°
6
93°
80°
7
91°
79°
8
94°
80°
9
94°
80°
10
93°
78°
11
94°
79°
12
92°
78°
13
91°
77°
14
93°
76°
15
91°
78°
16
91°
78°
17
92°
77°
18
92°
77°
19
93°
76°
20
92°
76°
21
90°
75°
22
90°
75°
23
91°
76°
24
90°
77°
25
92°
76°
26
90°
77°
27
90°
75°
28
92°
75°
29
90°
76°
30
90°
75°
31
91°
75°
1
91°
77°
2
90°
76°
3
89°
75°
4
90°
76°
5
89°
76°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Port Isabel
Port Isabel's August 2026 forecast shows daily high temperatures ranging from 89° to 94°, with overnight lows between 75° and 80°. The average high for August is 91° with an average low of 77°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Port Isabel. See also: September | October | November.
