Climate and average weather in Guayama

In Guayama, the weather is muggy, hot, wet, and partly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around September.

Best: early January to late April

Over the course of the year, the temperature in Guayama typically varies from 23°C to 28°C, and is rarely below 22°C or above 29°C. August is the hottest month of the year, while February is the coldest.

Based on the travel score, the best times of year to visit Guayama for warm-weather activities are from early January to late April and late November to late December.

Hottest
Aug
28°
Coldest
Feb
23°
Wettest
Sep
167 mm
Driest
Feb
38 mm
Rain / yr
1134 mm
244 wet days
Daylight
10.9–13.1 h
shortest–longest
Elevation
73 m
18.0°N
Clearest
Feb
36% cloud

Guayama weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early January to late April.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Guayama, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

Temperatures in Guayama stay fairly even through the year, without a distinct hot or cool season. The warmest month is August, with an average high of 28°C and low of 25°C; the coolest is February, with an average low of 23°C and high of 25°C.

Days typically run about 3°C warmer than nights year-round.

18°20°22°24°26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2523
Feb2523
Mar2623
Apr2623
May2724
Jun2825
Jul2825
Aug2825
Sep2825
Oct2825
Nov2724
Dec2623

How hot and cold Guayama really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Guayama feels like about 32°C (around August 26). About 40 days a year carry some heat stress, peaking in August.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan25252323
Feb25252323
Mar25262323
Apr26262323
May28272424
Jun31282525
Jul31282525
Aug32282525
Sep32282525
Oct31282525
Nov28272424
Dec26262323

Average hourly temperature in Guayama

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on August afternoons, near 28°C, and coldest before dawn in February, near 23°C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Guayama weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan25° / 23°4816.5116.2
Feb25° / 23°3814.711.46.3
Mar26° / 23°4614.411.96.4
Apr26° / 23°6317.112.45.7
May27° / 24°11622.512.84.7
Jun28° / 25°9521.913.14.6
Jul28° / 25°11323134.6
Aug28° / 25°13024.712.64.2
Sep28° / 25°16724.912.13.9
Oct28° / 25°14625.111.64.2
Nov27° / 24°11321.211.24.9
Dec26° / 23°6017.710.95.9

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Guayama gets about 1134 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 6.6 months, from around May 3 to Nov 20, peaking in September at about 85% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Mar 11.

September is the wettest month by volume, with 167 mm over about 25 wet days; February is the driest, with 38 mm.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetSep 20 · 85%Mar 11 · 43%
Rain on a day (%)Rain days
Jan5417
Feb5215
Mar4714
Apr5817
May7223
Jun7322
Jul7423
Aug7925
Sep8325
Oct8125
Nov7021
Dec5718

Monthly rainfall

Over a full year, Guayama collects about 1134 mm of rain across 244 wet days — roughly 94 mm in an average month.

It doesn’t fall evenly. September is the wettest month with 167 mm, while February is the driest at just 38 mm. The three wettest months alone bring about 39% of the year’s total.

0255075100125150175200JanFebMarAprMayJunJulAugSepOctNovDec483846631169511313016714611360
Rainfall (mm)Rain days
Jan4817
Feb3815
Mar4614
Apr6317
May11623
Jun9522
Jul11323
Aug13025
Sep16725
Oct14625
Nov11321
Dec6018

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Guayama, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around November 20 and lasts for 5.3 months, ending around April 28. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 91% of the time on average.

The cloudier part of the year begins around April 29 and lasts for 6.7 months, ending around November 19. The cloudiest month is September, when it is overcast or mostly cloudy 56% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecFeb 15 · 92%Sep 25 · 40%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan8911
Feb919
Mar8416
Apr7426
May4753
Jun4852
Jul6040
Aug5545
Sep4456
Oct4852
Nov6436
Dec8218

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 10, brings about 13 h 06 min of light; the shortest, around January 1, only 10 h 54 min — a swing of roughly 2 h 12 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan11.07:036:05
Feb11.46:576:21
Mar11.96:386:30
Apr12.46:126:37
May12.85:556:46
Jun13.15:536:57
Jul13.06:017:00
Aug12.66:106:47
Sep12.16:166:22
Oct11.66:225:57
Nov11.26:365:44
Dec10.96:535:48

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Guayama averages about 13 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 6 and 21 days.

The sunnier stretch runs 5.0 months, from around Nov 24 to Apr 25. The sunniest month is February, with roughly 20 sunny days (bright).

The greyest month is May, down near 7 sunny days — about 64% fewer than the February peak.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedbrightbrilliantFeb 1121 daysMay 286 days
Sunny daysSky
Jan20Bright
Feb18Bright
Mar17Bright
Apr13Mixed
May7Gloomy
Jun8Mixed
Jul13Mixed
Aug10Mixed
Sep7Gloomy
Oct8Mixed
Nov11Mixed
Dec17Bright

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

Guayama is humid all year round — on a typical day the air feels at least humid, and there is no real dry season to wait for.

The stickiest month is January, when it feels muggy, oppressive or miserable about 95% of the time. Even in February, the mildest month, the air is dry or comfortable only 0% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressivemuggyhumid
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan453420
Feb868240
Mar1060290
Apr334621
May05905
Jun008119
Jul007129
Aug005248
Sep005644
Oct007426
Nov08866
Dec326710

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Guayama is typically light breeze, near 16 km/h, and varies moderately with the seasons.

The windier part of the year lasts 2.6 months, from around Jun 6 to Aug 22. The windiest month is July, averaging about 19 km/h (light breeze).

The calmer part of the year runs from around Aug 23 to Dec 2, with October the calmest month at about 13 km/h.

0510152025JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmercalmlight breezebreezyJul 5 · 19 km/hOct 13 · 13 km/h
Wind speed (km/h)Feels
Jan17light breeze
Feb17light breeze
Mar16light breeze
Apr16light breeze
May16light breeze
Jun17light breeze
Jul19light breeze
Aug17light breeze
Sep14light breeze
Oct13light breeze
Nov15light breeze
Dec17light breeze

Hazard calendar for Guayama

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

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

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

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

Best time to visit Guayama

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Guayama throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid January, Guayama is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Guayama for general outdoor tourist activities is from late November to late April, with a peak score in the second week of March.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationMar 11 · 6.6

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan6.2good
Feb6.3good
Mar6.4good
Apr5.7good
May4.7fair
Jun4.6fair
Jul4.6fair
Aug4.2fair
Sep3.9fair
Oct4.2fair
Nov4.9fair
Dec5.9good

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best times of year to visit Guayama for hot-weather activities run from mid June to mid July and again from mid November to early May, with a peak score in the second week of March.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebest timebeach/pool scoretemperaturecloudsprecipitationMar 12 · 6.1

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Guayama, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

Guayama packs about the same all year — highs hold near 28°C. Across the year the things worth having are light clothes, rain gear and sun protection.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Guayama sees daytime highs around 28°C and nights near 25°C. Pack light clothes, rain gear and sun protection. About 25 days see rain.

Sea temperature near Guayama

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea offshore 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 (midday) in Guayama by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Guayama 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

Average hourly UV index in Guayama

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in April the burn window is concentrated in the middle of the day: about 8 hours a day reach index 3 (protection recommended), and 6.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan6.54
Feb75
Mar86
Apr86.5
May86
Jun8.56.5
Jul8.56
Aug86
Sep86
Oct75
Nov6.53.5
Dec62.5

Air quality in Guayama by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Guayama 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
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Guayama is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Guayama banks about 5,612 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around September.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan435
Feb388
Mar435
Apr439
May480
Jun486
Jul509
Aug515
Sep499
Oct505
Nov467
Dec456

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Guayama receives about 5.7 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.4 and 6.5 kWh/m².

The brighter stretch of the year lasts 6.7 months, from around Feb 27 to Sep 18. The brightest month is April, averaging about 6.5 kWh/m² (intense).

The dimmest month is December, down near 4.5 kWh/m² — roughly 32% less than the April peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseApr 156.5 kWhDec 204.4 kWh
Solar energy (kWh/m²)Level
Jan4.7Bright
Feb5.4Bright
Mar6.1Intense
Apr6.5Intense
May6.4Intense
Jun6.5Intense
Jul6.5Intense
Aug6.3Intense
Sep5.8Bright
Oct5.2Bright
Nov4.6Bright
Dec4.4Bright

Where is Guayama?

Guayama sits at 18.0°N, 66.1°W, 73 m above sea level, in Puerto Rico. The nearest listed city is Cayey, 15 km away.

CaguasHumacaoGuaynaboTrujillo AltoBayamónCarolinaCandelaria

Topography around Guayama

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

Within 3 km, the terrain around Guayama has significant variations in elevation — a maximum elevation change of 396 m around an average of 80 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 901 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,308 m.

The land around Guayama is covered by trees (56%) and artificial surfaces (25%) within 3 km, trees (46%) and water (38%) within 16 km, and water (58%) and trees (33%) within 80 km.

3 km
396 m
16 km
901 m
80 km
1,308 m
treesshrubsgrasslandcroplandartificial surfaceswatermangroves
Nearby: Cayey 15 km · Caguas 29 km · Humacao 35 km · Guaynabo 42 km · Trujillo Alto 43 km · Bayamón 46 km · Carolina 47 km · Candelaria 48 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 Guayama (17.9841°, -66.1138°, elevation 73 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).