Cayey weather in December

In December, Cayey sees average daytime highs of 26°C and overnight lows near 22°C, with 39 mm of rain across 11.6 wet days and about 10.9 hours of daylight. It is the 9th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 53% of the time in December, and the air most often feels muggy.

Daylight stretches from about 11 hours at the start of December to 10 h 54 min by month's end. Set against the rest of the year, December is Cayey's 3rd-clearest and 5th-windiest month. For the whole year in context, see Cayey's year-round climate.

Daytime high
26°
9th warmest
Overnight low
22°
5th coldest
Rainfall
39 mm
11.6 wet days
Daylight
10 h 54 min
6:53 AM – 5:48 PM
Cloud cover
44%
3rd clearest
Wind
16 km/h
5th windiest
Solar energy
4.46 kWh/m²
Travel score
6.7
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 26°C through the month.

A typical December day in Cayey reaches about 26°C in the afternoon and slips back to 22°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 27°C. Set against its neighbours, December runs about 1°C cooler than November and on par with January.

20°23°25°28°30°151015202531
Avg high (°C)Avg low (°C)
12723
22723
32723
42723
52723
62723
72722
82722
92722
102622
112622
122622
132622
142622
152622
162622
172622
182622
192622
202622
212622
222622
232622
242622
252622
262622
272622
282622
292622
302622
312622

How December really feels in Cayey

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Cayey weather by month

How December compares with the rest of the year at a glance. December is the 9th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 22°3210.8116.9
Feb26° / 21°279.411.47.0
Mar26° / 22°4010.811.96.8
Apr27° / 22°5913.712.46.1
May27° / 23°9818.212.85.3
Jun28° / 24°6415.913.15.2
Jul28° / 24°7515.5135.1
Aug29° / 24°9618.812.64.6
Sep28° / 24°14321.612.14.2
Oct28° / 24°12221.411.64.7
Nov27° / 23°911711.15.5
Dec26° / 22°3911.610.96.7

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 53% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 28% of December, with mostly cloudy or overcast conditions the remaining 19%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17624
27624
37723
47822
57822
67822
77921
87921
97921
107921
118020
128020
138020
148119
158119
168020
178020
188020
198119
208119
218119
228119
238119
248218
258218
268317
278317
288416
298515
308515
318614

Chance of precipitation in December

Any precipitation

Cayey gets around 39 mm of rain over 11.6 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 37% and peaks near 42% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
142
241
340
440
540
639
739
839
938
1038
1138
1237
1337
1437
1536
1636
1736
1836
1936
2036
2136
2236
2336
2436
2536
2636
2736
2836
2936
3036
3136

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the muggy band about 60% of days. Sticky, muggy-or-worse air turns up on roughly 94% of them.

0%25%50%75%100%151015202531
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1044353
2044551
3044748
4044847
5045046
6045244
7045343
8045442
9055441
10055540
11055639
12055738
13055738
14065737
15065836
16065935
17165835
18165934
19166033
20166132
21166330
22166429
23166528
24166627
25166825
26166924
27167023
28067321
29067420
30067618
31067717

Wind in December

Winds average 16 km/h in December.

Across December, daily wind ranges from about 15 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1716light breeze
1816light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2717light breeze
2817light breeze
2917light breeze
3017light breeze
3117light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 11 hours at the start of December to 10 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:45 AM to 7:00 AM, and sunset from 5:44 PM to 5:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.06:455:44
211.06:455:44
311.06:465:45
411.06:465:45
511.06:475:45
611.06:485:45
711.06:485:45
810.96:495:46
910.96:495:46
1010.96:505:46
1110.96:515:47
1210.96:515:47
1310.96:525:47
1410.96:525:48
1510.96:535:48
1610.96:535:48
1710.96:545:49
1810.96:545:49
1910.96:555:50
2010.96:555:50
2110.96:565:51
2210.96:565:51
2310.96:575:52
2410.96:575:52
2510.96:585:52
2610.96:585:53
2710.96:585:54
2810.96:595:54
2910.96:595:55
3010.97:005:55
3110.97:005:56

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.46 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 4.46 kWh/m² to a high of 6.55 kWh/m² in April across the year — December's 4.46 kWh/m² sits near the bottom.

024151015202531
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.5Bright
114.5Bright
124.5Bright
134.5Bright
144.5Bright
154.5Bright
164.5Bright
174.5Bright
184.5Bright
194.5Bright
204.5Bright
214.5Bright
224.5Bright
234.5Bright
244.5Bright
254.5Bright
264.5Bright
274.5Bright
284.5Bright
294.5Bright
304.5Bright
314.5Bright
Planning a trip in December

Hazard calendar for Cayey

In seasonPeak

None of Cayey's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Cayey sits in the Atlantic hurricane belt; the season peaks August–October.

Cayey's rainy season runs July–November, when most of the year's rain falls.

Cayey sees seasonal dust haze (July), heaviest in July.

Atlantic hurricane
Rainy season
Dust
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Cayey?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.7
Sightseeing
4th-best month of the year
6.5
Beach & pool
4th-best month of the year

December is a reasonable time to visit Cayey for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Cayey in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Cayey sees daytime highs around 26°C and nights near 22°C. Worth packing: light clothes and rain gear. About 12 days see rain.

light clothesrain gear

Sea temperature near Cayey in December

The nearest coast averages about 28°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 27 km away) is warmest in September at about 29°C and coldest in February near 26°C.

The water stays above 20°C all year — warm enough for a swim any month.

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb26Warm
Mar26Warm
Apr27Warm
May28Warm
Jun28Tropical
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov28Tropical
Dec28Warm

UV index in Cayey in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Cayey peaks around April 12 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 7 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highApr 12UV 13Dec 16UV 7
UV index (midday)Level
Jan8Very high
Feb10Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug12Extreme
Sep12Extreme
Oct10Very high
Nov8Very high
Dec7High

Air quality in Cayey in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Cayey is worst in July — around 25 µg/m³ PM2.5 (moderate), about 4.7× the cleanest month (January, 5 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1125 µg/m³Jan 15 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb7Good
Mar7Good
Apr9Good
May14Moderate
Jun24Moderate
Jul25Moderate
Aug20Moderate
Sep15Moderate
Oct15Moderate
Nov8Good
Dec5Good
Location & terrain

Where is Cayey?

Cayey sits at 18.1°N, 66.2°W, 397 m above sea level, in Puerto Rico. The nearest listed city is Guayama, 15 km away.

CaguasGuaynaboTrujillo AltoBayamónCandelariaHumacaoCataño

Topography around Cayey

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Cayey.

Within 3 km, the terrain around Cayey has significant variations in elevation — a maximum elevation change of 462 m around an average of 482 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 892 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,308 m.

The land around Cayey is covered by trees (68%) within 3 km, trees (81%) within 16 km, and water (60%) and trees (32%) within 80 km.

3 km
462 m
16 km
892 m
80 km
1,308 m
treesshrubsgrasslandartificial surfaceswater
December weather nearby: Guayama 15 km · Caguas 18 km · Guaynabo 28 km · Trujillo Alto 32 km · Bayamón 32 km · Candelaria 33 km · Humacao 36 km · Cataño 37 km

Puerto Rico travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 78% of US
price level, 2025
GDP per capita
$40,620
2025
Happiness
7.0 / 10
World Happiness, 2015
Safe drinking water
99%
of population, 2024
Homicide rate
14.6
per 100k, 2023
Income group
High
World Bank
Religion
Roman Catholic 56%Protestant 33%none 7%other 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Cayey (18.1119°, -66.166°, elevation 397 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).