S
M
T
W
T
F
S
26
87°
69°
27
86°
68°
28
84°
73°
29
85°
67°
30
88°
70°
1
88°
71°
2
92°
73°
3
80°
73°
4
83°
72°
5
87°
73°
6
88°
73°
7
91°
72°
8
91°
72°
9
91°
73°
10
91°
76°
11
90°
76°
12
91°
75°
13
94°
74°
14
93°
75°
15
92°
71°
16
89°
70°
17
88°
75°
18
88°
77°
19
87°
78°
20
88°
79°
21
86°
80°
22
88°
80°
23
88°
81°
24
88°
80°
25
86°
80°
26
87°
81°
27
86°
82°
28
85°
80°
29
86°
81°
30
83°
78°
31
84°
79°
1
86°
79°
2
85°
80°
3
87°
78°
4
86°
79°
5
86°
77°
6
85°
78°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Upper Keys
Upper Keys's May 2026 forecast shows daily high temperatures ranging from 83° to 87°, with overnight lows between 77° and 82°. The average high for May is 86° with an average low of 79°. 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 Upper Keys. See also: June | July | August.
