S
M
T
W
T
F
S
26
70°
34°
27
57°
45°
28
55°
45°
29
70°
39°
30
77°
43°
1
73°
45°
2
77°
50°
3
84°
48°
4
77°
48°
5
64°
55°
6
63°
50°
7
66°
46°
8
63°
46°
9
72°
46°
10
66°
48°
11
73°
54°
12
84°
48°
13
59°
52°
14
59°
48°
15
54°
43°
16
55°
41°
17
63°
36°
18
68°
45°
19
64°
45°
20
68°
50°
21
79°
45°
22
77°
46°
23
66°
50°
24
77°
48°
25
59°
47°
26
65°
46°
27
72°
48°
28
80°
49°
29
68°
45°
30
67°
41°
31
70°
45°
1
77°
51°
2
80°
50°
3
74°
50°
4
75°
50°
5
77°
51°
6
71°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Cowlitz
Cowlitz's May 2026 forecast shows daily high temperatures ranging from 59° to 80°, with overnight lows between 41° and 51°. The average high for May is 72° with an average low of 48°. 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 Cowlitz. See also: June | July | August.
