S
M
T
W
T
F
S
26
74°
59°
27
79°
59°
28
73°
58°
29
75°
56°
30
79°
54°
31
84°
56°
1
72°
58°
2
71°
56°
3
76°
53°
4
81°
58°
5
87°
59°
6
88°
59°
7
86°
59°
8
83°
58°
9
77°
55°
10
74°
55°
11
79°
55°
12
79°
58°
13
81°
56°
14
78°
56°
15
75°
57°
16
75°
58°
17
78°
58°
18
78°
56°
19
76°
57°
20
81°
58°
21
80°
58°
22
74°
57°
23
74°
58°
24
78°
57°
25
79°
56°
26
77°
56°
27
75°
56°
28
74°
54°
29
73°
57°
30
76°
56°
31
80°
61°
1
81°
61°
2
80°
60°
3
80°
61°
4
79°
60°
5
79°
60°
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 73° to 81°, with overnight lows between 54° and 61°. The average high for August is 78° with an average low of 58°. 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.
