S
M
T
W
T
F
S
26
64°
52°
27
64°
49°
28
71°
51°
29
74°
53°
30
74°
55°
1
75°
56°
2
77°
57°
3
64°
54°
4
65°
52°
5
66°
53°
6
73°
55°
7
78°
56°
8
75°
56°
9
81°
56°
10
82°
58°
11
90°
57°
12
64°
56°
13
74°
53°
14
77°
56°
15
76°
55°
16
78°
56°
17
80°
60°
18
81°
59°
19
80°
61°
20
79°
60°
21
81°
60°
22
79°
59°
23
80°
60°
24
82°
61°
25
81°
58°
26
75°
55°
27
76°
55°
28
79°
56°
29
77°
56°
30
76°
55°
31
76°
56°
1
81°
60°
2
85°
63°
3
85°
62°
4
84°
63°
5
85°
63°
6
85°
64°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Altadena
Altadena's May 2026 forecast shows daily high temperatures ranging from 64° to 85°, with overnight lows between 53° and 64°. The average high for May is 79° with an average low of 59°. 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 Altadena. See also: June | July | August.
