S
M
T
W
T
F
S
29
84°
74°
30
84°
73°
1
82°
72°
2
82°
74°
3
83°
73°
4
82°
73°
5
82°
72°
6
83°
73°
7
82°
73°
8
82°
72°
9
83°
73°
10
82°
73°
11
81°
72°
12
83°
73°
13
84°
72°
14
84°
71°
15
85°
71°
16
84°
72°
17
84°
71°
18
83°
71°
19
84°
70°
20
84°
71°
21
83°
71°
22
84°
70°
23
84°
71°
24
83°
71°
25
84°
70°
26
83°
71°
27
84°
70°
28
85°
71°
29
84°
70°
30
83°
71°
31
83°
71°
1
84°
70°
2
84°
71°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Guaynabo
Guaynabo's December 2026 forecast shows daily high temperatures ranging from 81° to 85°, with overnight lows between 70° and 74°. The average high for December is 83° with an average low of 72°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how December weather will actually feel in Guaynabo. See also: January | February | March.
