Climate and average weather in Ko Chang

In Ko Chang, the weather is oppressive, hot, wet, and partly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around July.

Best: early January to mid March

Over the course of the year, the temperature in Ko Chang typically varies from 25°C to 29°C, and is rarely below 22°C or above 30°C. April is the hottest month of the year, while February is the coldest.

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

Hottest
Apr
29°
Coldest
Feb
26°
Wettest
Jul
612 mm
Driest
Dec
18 mm
Rain / yr
3327 mm
223 wet days
Daylight
11.3–12.7 h
shortest–longest
Elevation
0 m
12.0°N
Clearest
Feb
40% cloud

Ko Chang 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 March.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Ko Chang stay fairly even through the year, without a distinct hot or cool season. The warmest month is April, with an average high of 29°C and low of 27°C; the coolest is February, with an average low of 26°C and high of 28°C.

Days typically run about 2°C warmer than nights year-round.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2825
Feb2826
Mar2827
Apr2927
May2927
Jun2927
Jul2826
Aug2826
Sep2826
Oct2826
Nov2926
Dec2925

How hot and cold Ko Chang 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, Ko Chang feels like about 36°C (around May 7). About 221 days a year carry some heat stress, peaking in May.

25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan30282525
Feb30282626
Mar32282727
Apr35292727
May36292727
Jun35292727
Jul34282626
Aug33282626
Sep32282626
Oct32282626
Nov32292626
Dec31292525

Average hourly temperature in Ko Chang

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 April afternoons, near 29°C, and coldest before dawn in February, near 26°C.

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

Ko Chang 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
Jan28° / 25°286.311.47.0
Feb28° / 26°266.511.67.1
Mar28° / 27°7113.211.95.6
Apr29° / 27°11517.112.34.5
May29° / 27°44827.912.53.1
Jun29° / 27°59528.612.73.0
Jul28° / 26°61229.912.63.0
Aug28° / 26°54729.412.43.1
Sep28° / 26°53728.612.13.3
Oct28° / 26°27823.111.74.0
Nov29° / 26°518.211.45.7
Dec29° / 25°183.811.36.6

Chance of rain

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

Ko Chang gets about 3327 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 6.0 months, from around Apr 23 to Oct 23, peaking in July at about 97% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 24.

July is the wettest month by volume, with 612 mm over about 30 wet days; December is the driest, with 18 mm.

0%10%20%30%40%50%60%70%80%90%100%110%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJul 18 · 97%Dec 24 · 9%
Rain on a day (%)Rain days
Jan206
Feb247
Mar4213
Apr5817
May8928
Jun9529
Jul9730
Aug9529
Sep9529
Oct7323
Nov298
Dec124

Monthly rainfall

Over a full year, Ko Chang collects about 3327 mm of rain across 223 wet days — roughly 277 mm in an average month.

It doesn’t fall evenly. July is the wettest month with 612 mm, while December is the driest at just 18 mm. The three wettest months alone bring about 53% of the year’s total.

050100150200250300350400450500550600650700JanFebMarAprMayJunJulAugSepOctNovDec2826711154485956125475372785118
Rainfall (mm)Rain days
Jan286
Feb267
Mar7113
Apr11517
May44828
Jun59529
Jul61230
Aug54729
Sep53729
Oct27823
Nov518
Dec184

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Ko Chang, 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 October 27 and lasts for 6.0 months, ending around April 26. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 74% of the time on average.

The cloudier part of the year begins around April 27 and lasts for 6.0 months, ending around October 26. The cloudiest month is September, when it is overcast or mostly cloudy 95% 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 5 · 77%Sep 10 · 4%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan6832
Feb7426
Mar6634
Apr4456
May1486
Jun694
Jul694
Aug694
Sep595
Oct2377
Nov5050
Dec6139

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 1, brings about 12 h 42 min of light; the shortest, around January 1, only 11 h 18 min — a swing of roughly 1 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan11.46:396:01
Feb11.66:376:13
Mar11.96:236:18
Apr12.36:036:19
May12.55:506:24
Jun12.75:506:32
Jul12.65:576:36
Aug12.46:036:27
Sep12.16:036:07
Oct11.76:045:48
Nov11.46:135:39
Dec11.36:285:46

Sunny days

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

Ko Chang averages about 7 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 17 days.

The sunnier stretch runs 5.8 months, from around Oct 31 to Apr 25. The sunniest month is February, with roughly 17 sunny days (bright).

The greyest month is July, down near 0 sunny days — about 98% fewer than the February peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedbrightFeb 517 daysJul 240 days
Sunny daysSky
Jan15Bright
Feb15Bright
Mar15Mixed
Apr9Mixed
May2Gloomy
Jun1Gloomy
Jul0Gloomy
Aug1Gloomy
Sep0Gloomy
Oct4Gloomy
Nov10Mixed
Dec13Mixed

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.

Ko Chang 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 February, when it feels muggy, oppressive or miserable about 94% of the time. Even in January, the mildest month, the air is dry or comfortable only 3% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecoppressivemiserablemuggyhumid
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan31124583
Feb1512748
Mar0036036
Apr0001981
May000397
Jun000793
Jul0001783
Aug0002377
Sep0004258
Oct0046531
Nov02186317
Dec21432457

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 Ko Chang is typically light breeze, near 14 km/h, and varies a lot with the seasons.

The windier part of the year lasts 4.2 months, from around May 17 to Sep 21. The windiest month is August, averaging about 19 km/h (light breeze).

The calmer part of the year runs from around Sep 22 to Dec 1, with October the calmest month at about 11 km/h.

0510152025JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmercalmlight breezebreezyAug 2 · 21 km/hOct 14 · 10 km/h
Wind speed (km/h)Feels
Jan12calm
Feb11calm
Mar12calm
Apr11calm
May14light breeze
Jun17light breeze
Jul19light breeze
Aug19light breeze
Sep15light breeze
Oct11calm
Nov13light breeze
Dec15light breeze

Hazard calendar for Ko Chang

In seasonPeak

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

Ko Chang sits in the Pacific typhoon belt; the season peaks July–October.

Ko Chang's monsoon runs May–October, when most of the year's rain falls.

Pacific typhoon
Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Best time to visit Ko Chang

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around early March, Ko Chang 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 Ko Chang for general outdoor tourist activities is from late November to mid March, with a peak score in the first week of February.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationFeb 5 · 7.3

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
Jan7.0good
Feb7.0good
Mar5.7good
Apr4.5fair
May3.2poor
Jun3.0poor
Jul3.0poor
Aug3.1poor
Sep3.3poor
Oct4.0fair
Nov5.7good
Dec6.6good

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 Ko Chang for hot-weather activities is from early November to mid March, with a peak score in the last week of December.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationDec 26 · 8.2

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 Ko Chang, 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.

Ko Chang packs about the same all year — highs hold near 29°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 April, Ko Chang sees daytime highs around 29°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection. About 17 days see rain.

Sea temperature near Ko Chang

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 21 km away) is warmest in May at about 31°C and coldest in January near 28°C.

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

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Tropical
Feb28Tropical
Mar29Tropical
Apr30Tropical
May31Tropical
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec29Tropical

UV index (midday) in Ko Chang 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 Ko Chang peaks around August 17 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 12 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highAug 17UV 14Dec 12UV 9
UV index (midday)Level
Jan10Very high
Feb10Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep12Extreme
Oct11Extreme
Nov9Very high
Dec9Very high

Average hourly UV index in Ko Chang

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 August the burn window is concentrated in the middle of the day: about 8.5 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)
Jan74.5
Feb7.55
Mar86
Apr86
May86
Jun86
Jul8.56.5
Aug8.56.5
Sep86
Oct7.55.5
Nov74.5
Dec6.54

Air quality in Ko Chang 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 Ko Chang is worst in February — around 25 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (November, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodFeb 1424 µg/m³Nov 1410 µg/m³
PM2.5 (µg/m³)Level
Jan20Moderate
Feb25Moderate
Mar20Moderate
Apr16Moderate
May12Moderate
Jun12Moderate
Jul14Moderate
Aug12Good
Sep11Good
Oct11Good
Nov10Good
Dec11Good
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Ko Chang 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. Ko Chang banks about 6,336 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around April.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan517
Feb473
Mar544
Apr546
May559
Jun529
Jul538
Aug534
Sep510
Oct534
Nov525
Dec527

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.

Ko Chang receives about 5.0 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.2 and 6.0 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Nov 7 to May 14. The brightest month is April, averaging about 6.0 kWh/m² (bright).

The dimmest month is September, down near 4.3 kWh/m² — roughly 28% less than the April peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerbrighterdimmoderatebrightintenseApr 116.0 kWhSep 184.2 kWh
Solar energy (kWh/m²)Level
Jan5.3Bright
Feb5.7Bright
Mar6.0Bright
Apr6.0Bright
May5.0Bright
Jun4.5Bright
Jul4.4Bright
Aug4.5Bright
Sep4.3Bright
Oct4.7Bright
Nov5.1Bright
Dec5.1Bright

Where is Ko Chang?

Ko Chang sits at 12.0°N, 102.3°E, 0 m above sea level, in Thailand. The nearest listed city is Laem Ngop, 17 km away.

Topography around Ko Chang

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

Within 3 km, the terrain around Ko Chang has large variations in elevation — a maximum elevation change of 647 m around an average of 114 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 735 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,628 m.

The land around Ko Chang is covered by trees (67%) and water (29%) within 3 km, water (74%) and trees (25%) within 16 km, and water (55%) and trees (38%) within 80 km.

3 km
647 m
16 km
735 m
80 km
1,628 m
treesgrasslandcroplandartificial surfaceswatermangroves
Nearby: Laem Ngop 17 km · Trat 32 km · Khao Saming 37 km · Laem Sing 54 km · Chanthaburi 66 km · Khlong Yai 71 km · Tha Mai 72 km · Koh Kong 88 km

Thailand travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C
230 V · 50 Hz
Prices
≈ 31% of US
price level, 2025
GDP per capita
$8,057
2025
Happiness
6.3 / 10
World Happiness, 2025
Homicide rate
4.8
per 100k, 2011
Road deaths
32.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 402
Religion
Buddhist 93%Muslim 5%Christian 1%other 1%

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 Ko Chang (12.0451°, 102.3003°, elevation 0 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).