S
M
T
W
T
F
S
26
63°
44°
27
75°
35°
28
72°
51°
29
65°
49°
30
52°
35°
1
57°
32°
2
48°
31°
3
60°
31°
4
73°
48°
5
74°
58°
6
57°
48°
7
60°
35°
8
63°
35°
9
67°
49°
10
63°
43°
11
63°
37°
12
69°
37°
13
66°
44°
14
54°
40°
15
66°
49°
16
77°
61°
17
86°
61°
18
86°
65°
19
84°
60°
20
72°
51°
21
71°
56°
22
73°
52°
23
70°
51°
24
70°
51°
25
74°
55°
26
75°
52°
27
73°
57°
28
76°
58°
29
75°
58°
30
75°
56°
31
70°
53°
1
70°
50°
2
71°
49°
3
69°
49°
4
71°
50°
5
76°
59°
6
80°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Washington
Washington's May 2026 forecast shows daily high temperatures ranging from 54° to 86°, with overnight lows between 40° and 65°. The average high for May is 73° with an average low of 54°. 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 Washington. See also: June | July | August.