S
M
T
W
T
F
S
26
60°
42°
27
65°
43°
28
64°
38°
29
63°
42°
30
66°
44°
1
66°
42°
2
64°
42°
3
67°
45°
4
68°
46°
5
67°
47°
6
69°
48°
7
69°
49°
8
70°
47°
9
69°
43°
10
62°
46°
11
60°
47°
12
69°
48°
13
68°
46°
14
67°
48°
15
71°
49°
16
72°
51°
17
73°
52°
18
73°
41°
19
68°
41°
20
65°
42°
21
66°
43°
22
65°
44°
23
63°
45°
24
62°
46°
25
67°
53°
26
73°
52°
27
75°
53°
28
67°
55°
29
74°
50°
30
78°
46°
31
68°
52°
1
74°
48°
2
78°
56°
3
82°
56°
4
79°
47°
5
73°
45°
6
68°
47°
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 60° to 82°, with overnight lows between 38° and 56°. The average high for May is 69° with an average low of 47°. 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.
