S
M
T
W
T
F
S
26
69°
49°
27
61°
55°
28
55°
40°
29
54°
41°
30
51°
40°
1
52°
36°
2
63°
31°
3
71°
50°
4
67°
44°
5
52°
36°
6
49°
30°
7
60°
35°
8
72°
37°
9
64°
44°
10
65°
34°
11
69°
32°
12
76°
54°
13
72°
45°
14
78°
42°
15
88°
53°
16
80°
54°
17
74°
57°
18
69°
59°
19
65°
43°
20
58°
37°
21
61°
46°
22
64°
53°
23
74°
53°
24
77°
57°
25
83°
61°
26
82°
60°
27
77°
60°
28
78°
59°
29
77°
58°
30
77°
59°
31
77°
57°
1
76°
58°
2
76°
56°
3
74°
52°
4
74°
55°
5
69°
49°
6
69°
56°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Waltham
Waltham's May 2026 forecast shows daily high temperatures ranging from 61° to 83°, with overnight lows between 46° and 61°. The average high for May is 74° with an average low of 56°. 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 Waltham. See also: June | July | August.
