S
M
T
W
T
F
S
26
71°
38°
27
58°
41°
28
61°
49°
29
72°
39°
30
81°
43°
1
74°
50°
2
74°
51°
3
91°
49°
4
76°
55°
5
65°
54°
6
68°
55°
7
71°
51°
8
69°
50°
9
79°
46°
10
70°
54°
11
80°
51°
12
84°
51°
13
64°
54°
14
64°
51°
15
57°
42°
16
58°
45°
17
65°
38°
18
71°
46°
19
67°
49°
20
73°
49°
21
84°
52°
22
78°
50°
23
78°
53°
24
74°
54°
25
64°
49°
26
68°
51°
27
70°
52°
28
67°
51°
29
67°
50°
30
71°
50°
31
75°
54°
1
70°
52°
2
77°
56°
3
76°
55°
4
74°
53°
5
69°
50°
6
75°
55°
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 64° to 84°, with overnight lows between 49° and 56°. The average high for May is 72° with an average low of 52°. 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.
