S
M
T
W
T
F
S
26
79°
57°
27
82°
60°
28
81°
56°
29
79°
57°
30
82°
59°
31
77°
55°
1
76°
54°
2
80°
57°
3
82°
58°
4
82°
59°
5
81°
59°
6
81°
58°
7
82°
60°
8
82°
62°
9
83°
63°
10
73°
54°
11
72°
52°
12
73°
52°
13
74°
54°
14
75°
56°
15
74°
53°
16
76°
61°
17
81°
62°
18
82°
62°
19
83°
59°
20
83°
55°
21
82°
53°
22
81°
53°
23
75°
60°
24
80°
60°
25
81°
56°
26
81°
56°
27
80°
57°
28
81°
52°
29
76°
53°
30
73°
54°
31
80°
52°
1
72°
52°
2
73°
53°
3
71°
59°
4
76°
58°
5
79°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in SeaTac
SeaTac's August 2026 forecast shows daily high temperatures ranging from 71° to 83°, with overnight lows between 52° and 63°. The average high for August is 78° with an average low of 57°. 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 SeaTac. See also: September | October | November.
