S
M
T
W
T
F
S
26
83°
65°
27
84°
72°
28
82°
67°
29
70°
61°
30
68°
57°
1
66°
54°
2
73°
47°
3
79°
46°
4
79°
59°
5
77°
64°
6
65°
54°
7
73°
55°
8
76°
61°
9
78°
66°
10
79°
57°
11
74°
54°
12
80°
61°
13
84°
64°
14
83°
66°
15
83°
65°
16
83°
67°
17
82°
64°
18
78°
65°
19
83°
62°
20
82°
66°
21
83°
65°
22
79°
67°
23
81°
67°
24
81°
66°
25
80°
67°
26
80°
67°
27
81°
66°
28
81°
68°
29
82°
68°
30
80°
66°
31
81°
65°
1
81°
66°
2
82°
67°
3
84°
69°
4
83°
70°
5
81°
70°
6
83°
69°
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 65° to 84°, with overnight lows between 54° and 70°. The average high for May is 80° with an average low of 65°. 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.
