Climate and average weather in Carolina

In Carolina, 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 mid April

Over the course of the year, the temperature in Carolina typically varies from 22°C to 30°C, and is rarely below 21°C or above 31°C. August is the hottest month of the year, while January is the coldest.

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

Hottest
Aug
30°
Coldest
Jan
23°
Wettest
Sep
131 mm
Driest
Feb
28 mm
Rain / yr
949 mm
174 wet days
Daylight
10.9–13.1 h
shortest–longest
Elevation
16 m
18.4°N
Clearest
Feb
37% cloud

Carolina 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 mid April.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Carolina stay fairly even through the year, without a distinct hot or cool season. The warmest month is August, with an average high of 30°C and low of 25°C; the coolest is January, with an average low of 23°C and high of 27°C.

Days typically run about 5°C warmer than nights year-round.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2723
Feb2722
Mar2823
Apr2823
May2924
Jun3025
Jul3025
Aug3025
Sep3025
Oct2925
Nov2824
Dec2723

How hot and cold Carolina 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, Carolina feels like about 36°C (around August 30). About 179 days a year carry some heat stress, peaking in August.

20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan27272223
Feb29272222
Mar29282223
Apr31282323
May32292424
Jun34302525
Jul34302525
Aug35302525
Sep35302525
Oct34292525
Nov31282424
Dec29272323

Average hourly temperature in Carolina

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 30°C, and coldest before dawn in January, near 23°C.

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

Carolina 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
Jan27° / 23°3910.4116.8
Feb27° / 22°287.611.47.1
Mar28° / 23°398.411.96.9
Apr28° / 23°721112.45.8
May29° / 24°11216.212.94.7
Jun30° / 25°6813.913.14.5
Jul30° / 25°8016.5134.4
Aug30° / 25°9518.712.64.0
Sep30° / 25°13120.812.13.7
Oct29° / 25°12520.511.64.0
Nov28° / 24°11218.211.14.9
Dec27° / 23°4812.210.96.4

Chance of rain

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

Carolina gets about 949 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 5.1 months, from around Jun 30 to Nov 30, peaking in September at about 72% 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 131 mm over about 21 wet days; February is the driest, with 28 mm.

0%10%20%30%40%50%60%70%80%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetSep 23 · 72%Mar 11 · 24%
Rain on a day (%)Rain days
Jan3410
Feb278
Mar278
Apr3811
May5116
Jun4814
Jul5217
Aug6119
Sep6921
Oct6721
Nov6018
Dec3912

Monthly rainfall

Over a full year, Carolina collects about 949 mm of rain across 174 wet days — roughly 79 mm in an average month.

It doesn’t fall evenly. September is the wettest month with 131 mm, while February is the driest at just 28 mm. The three wettest months alone bring about 39% of the year’s total.

0255075100125150175JanFebMarAprMayJunJulAugSepOctNovDec3928397211268809513112511248
Rainfall (mm)Rain days
Jan3910
Feb288
Mar398
Apr7211
May11216
Jun6814
Jul8017
Aug9519
Sep13121
Oct12521
Nov11218
Dec4812

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Carolina, 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 18 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 88% of the time on average.

The cloudier part of the year begins around April 29 and lasts for 6.7 months, ending around November 17. The cloudiest month is September, when it is overcast or mostly cloudy 55% 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 12 · 90%May 24 · 40%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan8614
Feb8812
Mar8119
Apr7228
May4654
Jun4951
Jul5941
Aug5644
Sep4555
Oct5248
Nov6436
Dec8119

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 6, 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)
Jan11.07:036:03
Feb11.46:576:20
Mar11.96:376:30
Apr12.46:126:37
May12.95:546:46
Jun13.15:516:57
Jul13.05:597:00
Aug12.66:096:47
Sep12.16:156:21
Oct11.66:225:56
Nov11.16:355:43
Dec10.96:535:47

Sunny days

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

Carolina 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 20 days.

The sunnier stretch runs 5.0 months, from around Nov 20 to Apr 21. The sunniest month is February, with roughly 19 sunny days (bright).

The greyest month is May, down near 7 sunny days — about 61% fewer than the February peak.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedbrightbrilliantFeb 1020 daysMay 276 days
Sunny daysSky
Jan19Bright
Feb18Bright
Mar17Bright
Apr13Mixed
May8Gloomy
Jun9Mixed
Jul12Mixed
Aug10Mixed
Sep7Gloomy
Oct9Mixed
Nov12Mixed
Dec18Bright

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.

Carolina 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 March, the mildest month, the air is dry or comfortable only 1% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressivemuggyhumid
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan1458370
Feb0972190
Mar11167200
Apr0444511
May009846
Jun0018416
Jul0007426
Aug0005347
Sep0004951
Oct0006634
Nov008829
Dec0329671

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 Carolina is typically light breeze, near 14 km/h, and varies moderately with the seasons.

The windier part of the year lasts 2.8 months, from around Jun 1 to Aug 25. The windiest month is July, averaging about 17 km/h (light breeze).

The calmer part of the year runs from around Aug 26 to Dec 11, with October the calmest month at about 11 km/h.

05101520JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmercalmlight breezeJul 6 · 17 km/hOct 16 · 11 km/h
Wind speed (km/h)Feels
Jan15light breeze
Feb15light breeze
Mar15light breeze
Apr14light breeze
May14light breeze
Jun16light breeze
Jul17light breeze
Aug15light breeze
Sep13light breeze
Oct11calm
Nov13light breeze
Dec14light breeze

Hazard calendar for Carolina

In seasonPeak

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

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

Carolina 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 Carolina

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid April, Carolina is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

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 Carolina for general outdoor tourist activities is from late November to mid April, with a peak score in the second week of February.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationFeb 8 · 7.2

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
Jan6.8good
Feb7.1good
Mar6.9good
Apr5.8good
May4.7fair
Jun4.5fair
Jul4.4fair
Aug4.0fair
Sep3.7fair
Oct4.0fair
Nov5.0fair
Dec6.4good

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

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationMar 13 · 7.4

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 Carolina, 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.

Carolina packs about the same all year — highs hold near 30°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, Carolina sees daytime highs around 30°C and nights near 25°C. Pack light clothes, rain gear and sun protection. About 19 days see rain.

Sea temperature near Carolina

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

The sea at the nearest coast (about 29 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
May27Warm
Jun28Warm
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov28Tropical
Dec27Warm

UV index (midday) in Carolina 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 Carolina peaks around April 13 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 7 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highApr 13UV 13Dec 16UV 7
UV index (midday)Level
Jan8Very high
Feb10Extreme
Mar12Extreme
Apr13Extreme
May11Extreme
Jun12Extreme
Jul12Extreme
Aug12Extreme
Sep12Extreme
Oct10Very high
Nov8Very high
Dec7High

Average hourly UV index in Carolina

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 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
May86
Jun8.56.5
Jul8.56
Aug86
Sep86
Oct75
Nov6.53.5
Dec62.5

Air quality in Carolina 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 Carolina is worst in July — around 24 µg/m³ PM2.5 (moderate), about 4.6× the cleanest month (January, 5 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1324 µg/m³Jan 15 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb7Good
Mar7Good
Apr8Good
May14Moderate
Jun23Moderate
Jul24Moderate
Aug20Moderate
Sep15Moderate
Oct15Moderate
Nov8Good
Dec5Good
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Carolina 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. Carolina banks about 5,956 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan455
Feb412
Mar467
Apr472
May514
Jun523
Jul546
Aug550
Sep529
Oct532
Nov484
Dec473

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.

Carolina receives about 5.7 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.3 and 6.6 kWh/m².

The brighter stretch of the year lasts 6.7 months, from around Mar 2 to Sep 21. The brightest month is June, averaging about 6.5 kWh/m² (intense).

The dimmest month is December, down near 4.4 kWh/m² — roughly 33% less than the June peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 286.6 kWhDec 204.3 kWh
Solar energy (kWh/m²)Level
Jan4.6Bright
Feb5.3Bright
Mar6.0Intense
Apr6.5Intense
May6.3Intense
Jun6.6Intense
Jul6.5Intense
Aug6.3Intense
Sep5.8Bright
Oct5.2Bright
Nov4.5Bright
Dec4.3Bright

Where is Carolina?

Carolina sits at 18.4°N, 66.0°W, 16 m above sea level, in Puerto Rico. The nearest listed city is Trujillo Alto, 6.0 km away.

GuaynaboCatañoSan JuanCaguasBayamónLevittownCandelaria

Topography around Carolina

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

Within 3 km, the terrain around Carolina has only modest variations in elevation — a maximum elevation change of 112 m around an average of 21 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 851 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,304 m.

The land around Carolina is covered by trees (46%) and artificial surfaces (43%) within 3 km, trees (45%), water (25%) and artificial surfaces (20%) within 16 km, and water (65%) and trees (27%) within 80 km.

3 km
112 m
16 km
851 m
80 km
1,304 m
treesgrasslandartificial surfacesbare terrainwaterwetlandmangroves
Nearby: Trujillo Alto 6.0 km · Guaynabo 16 km · Cataño 18 km · San Juan 18 km · Caguas 19 km · Bayamón 21 km · Levittown 25 km · Candelaria 27 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 Carolina (18.3808°, -65.9574°, elevation 16 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).