S
M
T
W
T
F
S
26
58°
28°
27
54°
27°
28
65°
28°
29
68°
41°
30
71°
34°
1
76°
35°
2
80°
41°
3
81°
43°
4
80°
40°
5
77°
42°
6
81°
43°
7
75°
45°
8
74°
34°
9
76°
39°
10
84°
40°
11
77°
41°
12
91°
42°
13
62°
39°
14
69°
42°
15
65°
41°
16
55°
37°
17
59°
33°
18
65°
35°
19
70°
36°
20
77°
40°
21
79°
43°
22
72°
40°
23
78°
44°
24
72°
44°
25
74°
43°
26
58°
42°
27
63°
41°
28
64°
42°
29
66°
48°
30
64°
44°
31
70°
51°
1
75°
51°
2
70°
50°
3
70°
50°
4
65°
42°
5
63°
41°
6
64°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Union
Union's May 2026 forecast shows daily high temperatures ranging from 55° to 79°, with overnight lows between 33° and 51°. The average high for May is 68° with an average low of 42°. 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 Union. See also: June | July | August.
