S
M
T
W
T
F
S
26
72°
38°
27
58°
43°
28
61°
46°
29
72°
40°
30
83°
46°
1
76°
49°
2
71°
53°
3
91°
53°
4
78°
52°
5
75°
51°
6
75°
50°
7
77°
51°
8
71°
53°
9
76°
49°
10
82°
52°
11
80°
53°
12
76°
50°
13
74°
50°
14
73°
51°
15
70°
49°
16
65°
53°
17
70°
48°
18
64°
46°
19
64°
44°
20
67°
48°
21
75°
51°
22
72°
49°
23
69°
47°
24
76°
54°
25
71°
49°
26
70°
48°
27
76°
55°
28
77°
55°
29
77°
54°
30
78°
55°
31
79°
56°
1
77°
54°
2
76°
53°
3
76°
50°
4
72°
48°
5
71°
48°
6
69°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Lake Oswego
Lake Oswego's May 2026 forecast shows daily high temperatures ranging from 64° to 91°, with overnight lows between 44° and 56°. The average high for May is 74° with an average low of 51°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Lake Oswego. See also: June | July | August.
