Arecibo weather in May

In May, Arecibo sees average daytime highs of 29°C and overnight lows near 24°C, with 165 mm of rain across 18.3 wet days and about 12.9 hours of daylight. It is the 6th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 18% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 12 h 42 min at the start of May to 13 hours by month's end. Set against the rest of the year, May is Arecibo's 11th-clearest and 10th-windiest month. For the whole year in context, see Arecibo's year-round climate.

Daytime high
29°
6th warmest
Overnight low
24°
7th coldest
Rainfall
165 mm
18.3 wet days
Daylight
12 h 54 min
5:57 AM – 6:49 PM
Cloud cover
65%
11th clearest
Wind
13 km/h
10th windiest
Solar energy
6.29 kWh/m²
Travel score
4.5
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical May day in Arecibo reaches about 29°C in the afternoon and slips back to 24°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 30°C. Set against its neighbours, May runs about 1°C warmer than April and about 1°C cooler than June.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12823
22823
32823
42823
52823
62823
72823
82823
92823
102823
112923
122923
132923
142923
152923
162924
172924
182924
192924
202924
212924
222924
232924
242924
252924
262924
272924
282924
292924
302924
312924

How May really feels in Arecibo

Once humidity and wind are folded in, May averages 13 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
13
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Arecibo weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 22°419.5117.0
Feb27° / 22°368.111.47.0
Mar27° / 22°591011.96.7
Apr28° / 22°10713.712.45.8
May29° / 24°16518.312.94.5
Jun30° / 24°9213.813.14.6
Jul30° / 25°7914.9134.5
Aug30° / 25°10119.612.63.9
Sep30° / 25°15422.312.13.6
Oct29° / 24°13821.411.64.0
Nov28° / 23°11317.511.15.2
Dec27° / 23°4811.410.96.6

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 18% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 27% of May, with mostly cloudy or overcast conditions the remaining 54%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16238
26139
36040
45842
55743
65644
75545
85446
95248
105149
115050
124852
134654
144456
154456
164258
174159
184159
194060
203961
213961
223763
233763
243664
253763
263763
273763
283862
293862
303961
314060

Chance of precipitation in May

Any precipitation

Arecibo gets around 165 mm of rain over 18.3 wet days in May, the wettest month. 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 61% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
154
255
355
456
557
658
758
859
960
1060
1161
1261
1361
1461
1561
1661
1760
1860
1960
2059
2159
2259
2359
2459
2558
2658
2758
2857
2957
3056
3155

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 84% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1126730
2125740
3125740
4124750
5123751
6121771
7120781
8119791
9118801
10116821
11115822
12014842
13013852
14011872
15010873
1609883
1708893
1807903
1906904
2006904
2105905
2205905
2304906
2404906
2504897
2604897
2703898
2803898
2903889
3003889
31038710

Wind in May

Winds average 13 km/h in May.

Across May, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1812light breeze
1912light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze
3112light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 42 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 18 minutes over May. Sunrise moves from 6:04 AM to 5:54 AM, and sunset from 6:44 PM to 6:55 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.76:046:44
212.76:046:44
312.76:036:45
412.76:036:45
512.76:026:45
612.76:016:46
712.76:016:46
812.86:006:46
912.86:006:47
1012.86:006:47
1112.85:596:47
1212.85:596:48
1312.85:586:48
1412.85:586:48
1512.95:576:49
1612.95:576:49
1712.95:576:49
1812.95:566:50
1912.95:566:50
2012.95:566:51
2112.95:566:51
2212.95:556:51
2312.95:556:52
2413.05:556:52
2513.05:556:53
2613.05:546:53
2713.05:546:53
2813.05:546:54
2913.05:546:54
3013.05:546:54
3113.05:546:55

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.29 kWh/m².

For context, solar energy here swings from a low near 4.4 kWh/m² to a high of 6.53 kWh/m² in June across the year — May's 6.29 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
16.4Intense
26.4Intense
36.4Intense
46.4Intense
56.4Intense
66.4Intense
76.4Intense
86.4Intense
96.3Intense
106.3Intense
116.3Intense
126.3Intense
136.3Intense
146.3Intense
156.3Intense
166.3Intense
176.3Intense
186.3Intense
196.3Intense
206.3Intense
216.3Intense
226.3Intense
236.3Intense
246.3Intense
256.3Intense
266.3Intense
276.3Intense
286.3Intense
296.3Intense
306.3Intense
316.3Intense
Planning a trip in May

Hazard calendar for Arecibo

In seasonPeak

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

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

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

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

Is May a good time to visit Arecibo?

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

4.5
Sightseeing
8th-best month of the year
5.7
Beach & pool
9th-best month of the year

May is a reasonable time to visit Arecibo for sightseeing.

What to pack for Arecibo in May

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

In May, Arecibo sees daytime highs around 29°C and nights near 24°C. Pack light clothes, rain gear and sun protection. About 18 days see rain.

light clothesrain gearsun protection

Sea temperature near Arecibo in May

The nearest coast averages about 27°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 19 km away) is warmest in September at about 29°C and coldest in March 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
May27Warm
Jun28Tropical
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov28Tropical
Dec27Warm

UV index in Arecibo in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Arecibo peaks around April 12 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 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 15UV 7
UV index (midday)Level
Jan8Very high
Feb10Extreme
Mar12Extreme
Apr13Extreme
May11Extreme
Jun12Extreme
Jul12Extreme
Aug12Extreme
Sep12Extreme
Oct10Very high
Nov8Very high
Dec7High

Air quality in Arecibo 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 Arecibo is worst in July — around 24 µg/m³ PM2.5 (moderate), about 4.8× the cleanest month (January, 5 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1324 µg/m³Jan 105 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb7Good
Mar7Good
Apr8Good
May14Moderate
Jun23Moderate
Jul24Moderate
Aug20Moderate
Sep15Moderate
Oct15Moderate
Nov7Good
Dec5Good
Location & terrain

Where is Arecibo?

Arecibo sits at 18.5°N, 66.7°W, 7 m above sea level, in Puerto Rico. The nearest listed city is Barceloneta, 19 km away.

BarcelonetaManatíVega BajaAguadillaYaucoPonceMayagüezCandelaria

Topography around Arecibo

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

Within 3 km, the terrain around Arecibo has only modest variations in elevation — a maximum elevation change of 80 m around an average of 7 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 408 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,307 m.

The land around Arecibo is covered by water (44%) and trees (20%) within 3 km, water (45%) and trees (35%) within 16 km, and water (55%) and trees (35%) within 80 km.

3 km
80 m
16 km
408 m
80 km
1,307 m
treesgrasslandartificial surfacesbare terrainwaterwetlandmangroves
May weather nearby: Barceloneta 19 km · Manatí 24 km · Vega Baja 35 km · Aguadilla 47 km · Yauco 51 km · Ponce 52 km · Mayagüez 54 km · Candelaria 54 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 Arecibo (18.4724°, -66.7157°, elevation 7 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).