Climate and average weather in Surat Thani

In Surat Thani, 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 October.

Best: early January to mid March

Over the course of the year, the temperature in Surat Thani typically varies from 24°C to 33°C, and is rarely below 23°C or above 35°C. April is the hottest month of the year, while December is the coldest.

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

Hottest
Apr
33°
Coldest
Dec
25°
Wettest
Oct
268 mm
Driest
Feb
31 mm
Rain / yr
1561 mm
207 wet days
Daylight
11.5–12.5 h
shortest–longest
Elevation
10 m
9.1°N
Clearest
Feb
49% cloud

Surat Thani is city in Surat Thani province, Thailand.

Air quality
Elevated
PM2.5 17 µg/m³ · 2019
Density
1,914/km²
people per km²
Founded
1930

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

Surat Thani 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 Surat Thani, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

Temperatures in Surat Thani stay fairly even through the year, without a distinct hot or cool season. The warmest month is April, with an average high of 33°C and low of 26°C; the coolest is December, with an average low of 25°C and high of 29°C.

Days typically run about 6°C warmer than nights year-round.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan3024
Feb3125
Mar3225
Apr3326
May3226
Jun3226
Jul3226
Aug3226
Sep3125
Oct3025
Nov2925
Dec2925

How hot and cold Surat Thani 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, Surat Thani feels like about 41°C (around April 30). Nearly every day a year carries some heat stress, and 83 of them tip into dangerous heat (feels-like above 39°C), peaking in April.

20°25°30°35°40°45°JanFebMarAprMayJunJulAugSepOctNovDecdangerous heat
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan33302424
Feb35312525
Mar38322525
Apr41332626
May41322626
Jun39322626
Jul38322626
Aug37322626
Sep37312525
Oct36302525
Nov35292525
Dec33292525

Average hourly temperature in Surat Thani

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 33°C, and coldest before dawn in December, near 25°C.

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

Surat Thani 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
Jan30° / 24°699.511.55.3
Feb31° / 25°314.811.75.2
Mar32° / 25°929.211.94.1
Apr33° / 26°11414.412.23.2
May32° / 26°12422.112.42.6
Jun32° / 26°9518.712.53.0
Jul32° / 26°8918.512.53.2
Aug32° / 26°10819.812.33.1
Sep31° / 25°15523.712.12.9
Oct30° / 25°26827.311.83.0
Nov29° / 25°26723.511.63.5
Dec29° / 25°14915.711.54.7

Chance of rain

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

Surat Thani gets about 1561 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 7.5 months, from around Apr 26 to Dec 10, peaking in October at about 89% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Feb 15.

October is the wettest month by volume, with 268 mm over about 27 wet days; February is the driest, with 31 mm.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecdrierwettermostly drysome rainoften wetvery wetOct 5 · 89%Feb 15 · 17%
Rain on a day (%)Rain days
Jan3010
Feb185
Mar309
Apr4914
May7022
Jun6219
Jul6019
Aug6320
Sep8024
Oct8727
Nov7824
Dec5116

Monthly rainfall

Over a full year, Surat Thani collects about 1561 mm of rain across 207 wet days — roughly 130 mm in an average month.

It doesn’t fall evenly. October is the wettest month with 268 mm, while February is the driest at just 31 mm. The three wettest months alone bring about 44% of the year’s total.

050100150200250300JanFebMarAprMayJunJulAugSepOctNovDec6931921141249589108155268267149
Rainfall (mm)Rain days
Jan6910
Feb315
Mar929
Apr11414
May12422
Jun9519
Jul8919
Aug10820
Sep15524
Oct26827
Nov26724
Dec14916

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Surat Thani, 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 23 and lasts for 5.3 months, ending around May 2. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 63% of the time on average.

The cloudier part of the year begins around May 3 and lasts for 6.7 months, ending around November 22. The cloudiest month is September, when it is overcast or mostly cloudy 91% 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%JanFebMarAprMayJunJulAugSepOctNovDecMar 4 · 67%Sep 30 · 9%clearmostly clearpartly cloudymostly cloudyovercastclearercloudierclearer
Clearer (%)Cloudier (%)
Jan4951
Feb6337
Mar5941
Apr4258
May1882
Jun1189
Jul1189
Aug991
Sep991
Oct1387
Nov2674
Dec3466

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 May 23, brings about 12 h 30 min of light; the shortest, around January 1, only 11 h 30 min — a swing of roughly 1 hour.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan11.56:466:18
Feb11.76:466:28
Mar11.96:346:30
Apr12.26:176:29
May12.46:066:31
Jun12.56:076:39
Jul12.56:146:43
Aug12.36:186:36
Sep12.16:156:18
Oct11.86:146:02
Nov11.66:215:55
Dec11.56:356:03

Sunny days

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

Surat Thani averages about 5 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 1 and 15 days.

The sunnier stretch runs 4.5 months, from around Dec 16 to Apr 30. The sunniest month is March, with roughly 13 sunny days (mixed).

The greyest month is August, down near 1 sunny days — about 94% fewer than the March peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyergloomymixedbrightMar 515 daysAug 31 days
Sunny daysSky
Jan9Mixed
Feb12Mixed
Mar13Mixed
Apr8Gloomy
May2Gloomy
Jun1Gloomy
Jul1Gloomy
Aug1Gloomy
Sep1Gloomy
Oct2Gloomy
Nov4Gloomy
Dec5Gloomy

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.

Surat Thani 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 100% of the time. Even in January, 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%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressivemuggy
Muggy (%)Oppressive (%)Miserable (%)
Jan97515
Feb58213
Mar16237
Apr02377
May01090
Jun02476
Jul04753
Aug05644
Sep04456
Oct02575
Nov13366
Dec86032

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 Surat Thani is typically calm, near 10 km/h, and varies moderately with the seasons.

The windier part of the year lasts 3.1 months, from around Nov 10 to Feb 12. The windiest month is December, averaging about 13 km/h (light breeze).

The calmer part of the year runs from around Sep 2 to Nov 9, with October the calmest month at about 8 km/h.

05101520JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeDec 19 · 13 km/hOct 12 · 8 km/h
Wind speed (km/h)Feels
Jan11calm
Feb10calm
Mar9calm
Apr8calm
May9calm
Jun11calm
Jul11calm
Aug11calm
Sep10calm
Oct8calm
Nov11calm
Dec13light breeze

Hazard calendar for Surat Thani

In seasonPeak

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

Surat Thani sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.

Surat Thani's rainy season runs May–May, when most of the year's rain falls.

Cyclone
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Best time to visit Surat Thani

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around early March, Surat Thani 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 Surat Thani for general outdoor tourist activities is from early December to mid March, with a peak score in the second week of January.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationJan 9 · 5.3

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
Jan5.3fair
Feb5.1fair
Mar4.1fair
Apr3.2poor
May2.7poor
Jun3.0poor
Jul3.1poor
Aug3.1poor
Sep2.9poor
Oct3.0poor
Nov3.6fair
Dec4.7fair

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 Surat Thani for hot-weather activities is from mid December to late March, with a peak score in the second week of February.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationFeb 12 · 7.5

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 Surat Thani, 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.

Surat Thani packs about the same all year — highs hold near 33°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, Surat Thani sees daytime highs around 33°C and nights near 26°C. Pack light clothes, rain gear and sun protection. About 14 days see rain.

Sea temperature near Surat Thani

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 27 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
Jan28Warm
Feb28Tropical
Mar29Tropical
Apr30Tropical
May31Tropical
Jun30Tropical
Jul30Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index (midday) in Surat Thani 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 Surat Thani peaks around August 21 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highAug 21UV 13Dec 16UV 10
UV index (midday)Level
Jan10Extreme
Feb12Extreme
Mar13Extreme
Apr13Extreme
May12Extreme
Jun12Extreme
Jul11Extreme
Aug14Extreme
Sep13Extreme
Oct12Extreme
Nov10Extreme
Dec10Very high

Average hourly UV index in Surat Thani

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 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)
Jan7.55
Feb7.55.5
Mar86
Apr86
May86
Jun86
Jul86
Aug86.5
Sep86
Oct7.55.5
Nov75
Dec75

Air quality in Surat Thani 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 Surat Thani is worst in April — around 21 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Seasonal pattern from CAMS reanalysis, scaled to Surat Thani's WHO annual average of 17 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1021 µg/m³Aug 2014 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb19Moderate
Mar21Moderate
Apr21Moderate
May17Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep15Moderate
Oct15Moderate
Nov15Moderate
Dec15Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Surat Thani 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. Surat Thani banks about 6,615 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)
Jan525
Feb494
Mar579
Apr585
May598
Jun567
Jul577
Aug574
Sep540
Oct541
Nov514
Dec522

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.

Surat Thani receives about 5.2 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.1 and 6.3 kWh/m².

The brighter stretch of the year lasts 4.8 months, from around Jan 22 to Jun 17. The brightest month is March, averaging about 6.2 kWh/m² (intense).

The dimmest month is November, down near 4.1 kWh/m² — roughly 34% less than the March peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerdimmoderatebrightintenseMar 106.3 kWhNov 274.1 kWh
Solar energy (kWh/m²)Level
Jan5.0Bright
Feb5.9Bright
Mar6.3Intense
Apr6.2Intense
May5.5Bright
Jun5.2Bright
Jul5.1Bright
Aug5.1Bright
Sep4.9Bright
Oct4.4Bright
Nov4.1Bright
Dec4.3Bright

Where is Surat Thani?

Surat Thani sits at 9.1°N, 99.3°E, 10 m above sea level, in Thailand. The nearest listed city is Tha Kham, 12 km away.

Lang SuanKo Pha-nganNakhon Si ThammaratThung SongKo Tao

Topography around Surat Thani

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

Within 3 km, the terrain around Surat Thani has only modest variations in elevation — a maximum elevation change of 35 m around an average of 6 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 308 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,599 m.

The land around Surat Thani is covered by artificial surfaces (45%) and trees (35%) within 3 km, trees (57%) and water (23%) within 16 km, and trees (68%) and water (29%) within 80 km.

3 km
35 m
16 km
308 m
80 km
1,599 m
treesgrasslandcroplandartificial surfacesbare terrainwatermangroves
Nearby: Tha Kham 12 km · Ban Na San 38 km · Ko Samui 79 km · Lang Suan 94 km · Ko Pha-ngan 103 km · Nakhon Si Thammarat 105 km · Thung Song 115 km · Ko Tao 119 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 Surat Thani (9.1401°, 99.3331°, elevation 10 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).