S
M
T
W
T
F
S
26
54°
43°
27
68°
38°
28
59°
47°
29
58°
50°
30
62°
39°
1
64°
34°
2
54°
41°
3
62°
36°
4
74°
36°
5
84°
46°
6
70°
55°
7
67°
51°
8
67°
38°
9
66°
49°
10
70°
45°
11
63°
49°
12
70°
41°
13
67°
45°
14
57°
46°
15
71°
50°
16
82°
44°
17
87°
54°
18
95°
58°
19
94°
65°
20
89°
66°
21
58°
53°
22
59°
49°
23
51°
48°
24
63°
58°
25
69°
60°
26
75°
59°
27
78°
57°
28
75°
53°
29
76°
56°
30
77°
58°
31
80°
60°
1
76°
57°
2
77°
55°
3
76°
56°
4
81°
60°
5
82°
61°
6
82°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Mercersburg
Mercersburg's May 2026 forecast shows daily high temperatures ranging from 51° to 82°, with overnight lows between 48° and 61°. The average high for May is 73° with an average low of 57°. 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 Mercersburg. See also: June | July | August.
