S
M
T
W
T
F
S
26
85°
59°
27
87°
61°
28
87°
61°
29
79°
57°
30
79°
55°
31
78°
56°
1
78°
56°
2
79°
55°
3
82°
56°
4
80°
56°
5
80°
58°
6
81°
61°
7
79°
57°
8
85°
60°
9
88°
62°
10
88°
61°
11
87°
60°
12
88°
62°
13
87°
61°
14
87°
61°
15
86°
60°
16
84°
61°
17
87°
61°
18
87°
60°
19
86°
61°
20
86°
61°
21
87°
60°
22
86°
61°
23
87°
62°
24
84°
54°
25
80°
60°
26
84°
61°
27
85°
62°
28
87°
61°
29
88°
57°
30
87°
54°
31
85°
61°
1
86°
59°
2
85°
59°
3
86°
55°
4
86°
52°
5
84°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Lake Oswego
Lake Oswego's August 2026 forecast shows daily high temperatures ranging from 78° to 88°, with overnight lows between 51° and 62°. The average high for August is 84° with an average low of 59°. 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 Lake Oswego. See also: September | October | November.
