S
M
T
W
T
F
S
26
61°
49°
27
73°
47°
28
61°
52°
29
61°
46°
30
57°
41°
1
51°
38°
2
51°
34°
3
61°
36°
4
76°
49°
5
68°
45°
6
55°
43°
7
59°
40°
8
64°
46°
9
72°
53°
10
64°
49°
11
70°
42°
12
74°
42°
13
61°
46°
14
65°
42°
15
66°
44°
16
79°
57°
17
85°
62°
18
86°
66°
19
85°
67°
20
71°
53°
21
65°
49°
22
64°
51°
23
64°
57°
24
73°
57°
25
77°
53°
26
80°
60°
27
77°
59°
28
76°
51°
29
75°
51°
30
69°
46°
31
69°
49°
1
73°
49°
2
74°
52°
3
77°
55°
4
77°
57°
5
78°
57°
6
76°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Portland
Portland's May 2026 forecast shows daily high temperatures ranging from 69° to 80°, with overnight lows between 46° and 60°. The average high for May is 75° with an average low of 53°. 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 Portland. See also: June | July | August.
