S
M
T
W
T
F
S
26
65°
31°
27
73°
37°
28
69°
46°
29
56°
46°
30
49°
39°
1
53°
31°
2
48°
36°
3
54°
38°
4
67°
45°
5
70°
44°
6
48°
42°
7
53°
37°
8
53°
35°
9
65°
37°
10
57°
39°
11
53°
33°
12
58°
34°
13
56°
44°
14
53°
43°
15
60°
47°
16
N/A
17
74°
48°
18
84°
67°
19
82°
65°
20
70°
39°
21
57°
38°
22
64°
46°
23
64°
50°
24
65°
52°
25
68°
49°
26
65°
51°
27
66°
52°
28
68°
50°
29
67°
47°
30
71°
51°
31
64°
49°
1
67°
49°
2
68°
52°
3
66°
53°
4
66°
53°
5
68°
52°
6
73°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Portland
Portland's May 2026 forecast shows daily high temperatures ranging from 57° to 84°, with overnight lows between 38° and 67°. The average high for May is 68° 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 Portland. See also: June | July | August.
