S
M
T
W
T
F
S
26
65°
39°
27
71°
35°
28
65°
38°
29
60°
45°
30
52°
45°
1
62°
40°
2
59°
44°
3
54°
35°
4
73°
36°
5
85°
52°
6
73°
53°
7
63°
43°
8
60°
36°
9
50°
34°
10
74°
48°
11
62°
40°
12
63°
37°
13
59°
40°
14
59°
50°
15
57°
46°
16
79°
43°
17
88°
55°
18
80°
57°
19
95°
56°
20
87°
67°
21
69°
48°
22
68°
40°
23
66°
45°
24
54°
52°
25
78°
52°
26
86°
52°
27
88°
65°
28
73°
51°
29
70°
49°
30
55°
38°
31
68°
45°
1
63°
41°
2
72°
49°
3
80°
52°
4
85°
57°
5
84°
64°
6
83°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Merrimack
Merrimack's May 2026 forecast shows daily high temperatures ranging from 63° to 85°, with overnight lows between 41° and 64°. The average high for May is 76° with an average low of 52°. 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 Merrimack. See also: June | July | August.
