Cayey weather in May

In May, Cayey sees average daytime highs of 27°C and overnight lows near 23°C, with 98 mm of rain across 18.2 wet days and about 12.8 hours of daylight. It is the 6th-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 21% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 12 h 36 min at the start of May to 13 hours by month's end. Set against the rest of the year, May is Cayey's 11th-clearest and 8th-windiest month. For the whole year in context, see Cayey's year-round climate.

Daytime high
27°
6th warmest
Overnight low
23°
7th coldest
Rainfall
98 mm
18.2 wet days
Daylight
12 h 48 min
5:55 AM – 6:46 PM
Cloud cover
65%
11th clearest
Wind
15 km/h
8th windiest
Solar energy
6.41 kWh/m²
Travel score
5.3
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical May day in Cayey reaches about 27°C in the afternoon and slips back to 23°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 28°C. Set against its neighbours, May runs on par with April and about 1°C cooler than June.

20°23°25°28°30°151015202531
Avg high (°C)Avg low (°C)
12723
22723
32723
42723
52723
62723
72723
82723
92723
102723
112723
122723
132723
142723
152723
162723
172723
182723
192723
202723
212723
222723
232723
242724
252724
262724
272824
282824
292824
302824
312824

How May really feels in Cayey

Once humidity and wind are folded in, May 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

May 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 May compares with the rest of the year at a glance. May is the 6th-warmest and 3rd-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 22% of May, with mostly cloudy or overcast conditions the remaining 56%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16139
26139
35941
45644
55545
65347
75149
84951
94852
104654
114555
124357
134357
144159
154060
164060
173961
183961
193862
203862
213763
223763
233763
243664
253763
263862
273862
283862
293862
303961
313961

Chance of precipitation in May

Any precipitation

Cayey gets around 98 mm of rain over 18.2 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 58% and peaks near 60% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
154
255
355
456
557
658
758
859
959
1059
1160
1260
1360
1459
1559
1659
1759
1858
1958
2058
2158
2257
2358
2458
2558
2658
2758
2858
2957
3057
3157

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the oppressive band about 77% of days. Sticky, muggy-or-worse air turns up on roughly 99% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1246520
2244540
3243550
4241570
5239590
6237610
7235630
8233650
9231670
10229690
11127720
12125740
13123760
14121780
15020800
16018820
17016840
18014860
19013870
20012880
21011881
22010891
23010891
2409901
2509892
2609892
2709892
2809892
2908902
3008902
3108902

Wind in May

Winds average 15 km/h in May.

Across May, daily wind ranges from about 15 km/h on the calmest days to 15 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
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze
3115light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 36 min at the start of May to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 24 minutes over May. Sunrise moves from 6:02 AM to 5:52 AM, and sunset from 6:41 PM to 6:52 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.66:026:41
212.76:026:42
312.76:016:42
412.76:016:42
512.76:006:43
612.76:006:43
712.75:596:43
812.75:596:44
912.85:586:44
1012.85:586:44
1112.85:576:45
1212.85:576:45
1312.85:576:45
1412.85:566:46
1512.85:566:46
1612.85:556:46
1712.95:556:47
1812.95:556:47
1912.95:546:47
2012.95:546:48
2112.95:546:48
2212.95:546:49
2312.95:536:49
2412.95:536:49
2512.95:536:50
2613.05:536:50
2713.05:536:50
2813.05:526:51
2913.05:526:51
3013.05:526:52
3113.05:526:52

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.41 kWh/m².

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 — May's 6.41 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.5Intense
26.5Intense
36.5Intense
46.5Intense
56.5Intense
66.5Intense
76.5Intense
86.5Intense
96.5Intense
106.5Intense
116.4Intense
126.4Intense
136.4Intense
146.4Intense
156.4Intense
166.4Intense
176.4Intense
186.4Intense
196.4Intense
206.4Intense
216.4Intense
226.4Intense
236.4Intense
246.4Intense
256.4Intense
266.4Intense
276.4Intense
286.4Intense
296.4Intense
306.4Intense
316.4Intense
Planning a trip in May

Hazard calendar for Cayey

In seasonPeak

In May, Cayey sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

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 May a good time to visit Cayey?

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

5.3
Sightseeing
7th-best month of the year
5.4
Beach & pool
10th-best month of the year

May is a reasonable time to visit Cayey for sightseeing.

What to pack for Cayey in May

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

In May, Cayey sees daytime highs around 27°C and nights near 23°C. Pack light clothes, rain gear and sun protection. About 18 days see rain.

light clothesrain gearsun protection

Sea temperature near Cayey in May

The nearest coast averages about 28°C in May — 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 12 (very high — sun protection essential). 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 May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May 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
May 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).