Climate and average weather in Khlong Yai

In Khlong Yai, the weather is muggy, hot, wet, and mostly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around August.

Best: mid November to late February

Over the course of the year, the temperature in Khlong Yai typically varies from 21°C to 31°C, and is rarely below 19°C or above 33°C. April is the hottest month of the year, while July is the coldest.

Based on the travel score, the best time of year to visit Khlong Yai for warm-weather activities is from mid November to late February.

Hottest
Apr
31°
Coldest
Jul
24°
Wettest
Aug
583 mm
Driest
Dec
38 mm
Rain / yr
3520 mm
269 wet days
Daylight
11.3–12.7 h
shortest–longest
Elevation
45 m
11.8°N
Clearest
Feb
55% cloud

Khlong Yai is subdistrict municipality in Trat province, Thailand.

Founded
1955

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Khlong Yai 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 mid November to late February.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Khlong Yai stay fairly even through the year, without a distinct hot or cool season. The warmest month is April, with an average high of 31°C and low of 24°C; the coolest is July, with an average low of 24°C and high of 28°C.

Days typically run about 7°C warmer than nights, with the widest day–night swing (around 10°C) in January.

15°20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan3121
Feb3122
Mar3123
Apr3124
May3024
Jun2924
Jul2824
Aug2824
Sep2923
Oct3023
Nov3122
Dec3122

How hot and cold Khlong Yai 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, Khlong Yai feels like about 37°C (around April 29). About 358 days a year carry some heat stress, peaking in April.

20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDecdangerous heat
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan33312121
Feb33312222
Mar35312323
Apr37312324
May36302424
Jun34292424
Jul33282424
Aug33282324
Sep32292323
Oct34302323
Nov34312222
Dec33312222

Average hourly temperature in Khlong Yai

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 31°C, and coldest before dawn in July, near 24°C.

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

Khlong Yai 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
Jan31° / 21°569.511.44.6
Feb31° / 22°7813.311.64.2
Mar31° / 23°15921.911.93.4
Apr31° / 24°21526.312.32.7
May30° / 24°33729.612.52.6
Jun29° / 24°47129.112.72.8
Jul28° / 24°58230.412.62.9
Aug28° / 24°58330.612.42.9
Sep29° / 23°51229.612.12.8
Oct30° / 23°37527.311.73.0
Nov31° / 22°11514.711.54.0
Dec31° / 22°386.711.34.8

Chance of rain

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

Khlong Yai gets about 3520 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 7.3 months, from around Mar 20 to Oct 26, peaking in August at about 99% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Dec 23.

August is the wettest month by volume, with 583 mm over about 31 wet days; December is the driest, with 38 mm.

0%10%20%30%40%50%60%70%80%90%100%110%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetAug 1 · 99%Dec 23 · 19%
Rain on a day (%)Rain days
Jan3010
Feb4813
Mar7122
Apr8726
May9530
Jun9729
Jul9830
Aug9931
Sep9930
Oct8627
Nov4915
Dec237

Monthly rainfall

Over a full year, Khlong Yai collects about 3520 mm of rain across 269 wet days — roughly 293 mm in an average month.

It doesn’t fall evenly. August is the wettest month with 583 mm, while December is the driest at just 38 mm. The three wettest months alone bring about 48% of the year’s total.

050100150200250300350400450500550600650JanFebMarAprMayJunJulAugSepOctNovDec567815921533747158258351237511538
Rainfall (mm)Rain days
Jan5610
Feb7813
Mar15922
Apr21526
May33730
Jun47129
Jul58230
Aug58331
Sep51230
Oct37527
Nov11515
Dec387

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Khlong Yai, 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 29 and lasts for 5.9 months, ending around April 25. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 57% of the time on average.

The cloudier part of the year begins around April 26 and lasts for 6.1 months, ending around October 28. The cloudiest month is September, when it is overcast or mostly cloudy 98% 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 10 · 59%Sep 8 · 1%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan5545
Feb5743
Mar4951
Apr3268
May991
Jun397
Jul298
Aug298
Sep298
Oct1387
Nov4159
Dec4951

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 4, 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)
Jan11.46:365:59
Feb11.66:356:11
Mar11.96:216:16
Apr12.36:016:17
May12.55:486:21
Jun12.75:486:29
Jul12.65:556:33
Aug12.46:016:24
Sep12.16:016:05
Oct11.76:015:45
Nov11.56:105:37
Dec11.36:255:44

Sunny days

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

Khlong Yai averages about 4 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 9 days.

The sunnier stretch runs 5.8 months, from around Oct 27 to Apr 21. The sunniest month is February, with roughly 8 sunny days (mixed).

The greyest month is May, down near 1 sunny days — about 92% fewer than the February peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyersunniergloomymixedFeb 119 daysMay 270 days
Sunny daysSky
Jan9Mixed
Feb8Mixed
Mar7Gloomy
Apr4Gloomy
May1Gloomy
Jun0Gloomy
Jul0Gloomy
Aug0Gloomy
Sep0Gloomy
Oct2Gloomy
Nov6Gloomy
Dec7Gloomy

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.

Khlong Yai 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 March, when it feels muggy, oppressive or miserable about 99% of the time. Even in December, the mildest month, the air is dry or comfortable only 8% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecDec 28 · 12%Mar 7 · 0%miserablemuggyoppressivehumidcomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan291731420
Feb13823632
Mar00158311
Apr00005545
May00002872
Jun00003664
Jul00005842
Aug00005743
Sep00007327
Oct00048213
Nov01523684
Dec172133371

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 Khlong Yai is typically calm, near 6 km/h, and varies little with the seasons.

The windier part of the year lasts 3.7 months, from around Jun 1 to Sep 22. The windiest month is August, averaging about 8 km/h (calm).

The calmer part of the year runs from around Jan 1 to May 31, with April the calmest month at about 5 km/h.

051015JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmercalmlight breezeAug 3 · 8 km/hApr 5 · 5 km/h
Wind speed (km/h)Feels
Jan5calm
Feb5calm
Mar5calm
Apr5calm
May5calm
Jun6calm
Jul8calm
Aug8calm
Sep6calm
Oct5calm
Nov5calm
Dec6calm

Hazard calendar for Khlong Yai

In seasonPeak

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

Khlong Yai sits in the Pacific typhoon belt; the season peaks July–October.

Khlong Yai'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 Khlong Yai

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid February, Khlong Yai 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 Khlong Yai for general outdoor tourist activities is from mid November to late February, with a peak score in the last week of December.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationDec 22 · 4.9

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
Jan4.6fair
Feb4.2fair
Mar3.4poor
Apr2.7poor
May2.6poor
Jun2.8poor
Jul2.9poor
Aug2.9poor
Sep2.9poor
Oct3.0poor
Nov4.0fair
Dec4.8fair

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 Khlong Yai for hot-weather activities is from mid November to mid February, with a peak score in the last week of December.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationDec 24 · 7.2

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 Khlong Yai, 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.

Khlong Yai packs about the same all year — highs hold near 31°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, Khlong Yai sees daytime highs around 31°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 26 days see rain.

Sea temperature near Khlong Yai

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 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
Feb29Tropical
Mar29Tropical
Apr30Tropical
May31Tropical
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec29Tropical

UV index (midday) in Khlong Yai 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 Khlong Yai peaks around August 18 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highAug 18UV 14Dec 13UV 9
UV index (midday)Level
Jan10Very high
Feb11Extreme
Mar13Extreme
Apr12Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug14Extreme
Sep13Extreme
Oct11Extreme
Nov9Very high
Dec9Very high

Average hourly UV index in Khlong Yai

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)
Jan75
Feb7.55
Mar86
Apr86
May86
Jun86
Jul8.56.5
Aug8.56.5
Sep86
Oct7.55.5
Nov74.5
Dec6.54.5

Air quality in Khlong Yai 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 Khlong Yai is worst in February — around 40 µg/m³ PM2.5 (poor), about 3.8× the cleanest month (November, 11 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateGoodFeb 1539 µg/m³Nov 1411 µg/m³
PM2.5 (µg/m³)Level
Jan28Moderate
Feb40Poor
Mar27Moderate
Apr19Moderate
May13Moderate
Jun12Moderate
Jul13Moderate
Aug12Good
Sep11Good
Oct11Good
Nov11Good
Dec12Good
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Khlong Yai 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. Khlong Yai banks about 5,969 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)
Jan494
Feb452
Mar517
Apr517
May528
Jun492
Jul494
Aug494
Sep477
Oct506
Nov497
Dec502

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.

Khlong Yai receives about 4.8 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.8 and 5.8 kWh/m².

The brighter stretch of the year lasts 6.4 months, from around Nov 3 to May 16. The brightest month is April, averaging about 5.7 kWh/m² (bright).

The dimmest month is September, down near 3.9 kWh/m² — roughly 31% less than the April peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerbrighterdimmoderatebrightintenseApr 105.8 kWhSep 183.8 kWh
Solar energy (kWh/m²)Level
Jan5.2Bright
Feb5.5Bright
Mar5.7Bright
Apr5.7Bright
May4.9Bright
Jun4.3Bright
Jul4.0Bright
Aug4.0Bright
Sep3.9Moderate
Oct4.4Bright
Nov4.9Bright
Dec4.9Bright

Where is Khlong Yai?

Khlong Yai sits at 11.8°N, 102.9°E, 45 m above sea level, in Thailand. The nearest listed city is Koh Kong, 21 km away.

Laem SingPailin

Topography around Khlong Yai

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

Within 3 km, the terrain around Khlong Yai has significant variations in elevation — a maximum elevation change of 324 m around an average of 57 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 741 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,728 m.

The land around Khlong Yai is covered by trees (52%) and water (34%) within 3 km, trees (49%) and water (44%) within 16 km, and trees (52%) and water (42%) within 80 km.

3 km
324 m
16 km
741 m
80 km
1,728 m
treesgrasslandcroplandartificial surfaceswatermangroves
Nearby: Koh Kong 21 km · Smach Mean Chey 30 km · Trat 66 km · Laem Ngop 69 km · Ko Chang 71 km · Khao Saming 81 km · Laem Sing 118 km · Pailin 123 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 Khlong Yai (11.7765°, 102.8873°, elevation 45 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).