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August Weather in Ko Samui Thailand

Daily high temperatures are around 89°F, rarely falling below 87°F or exceeding 92°F.

Daily low temperatures are around 80°F, rarely falling below 79°F or exceeding 81°F.

For reference, on May 6, the hottest day of the year, temperatures in Ko Samui typically range from 81°F to 91°F, while on January 4, the coldest day of the year, they range from 78°F to 85°F.

Average High and Low Temperature in August in Ko Samui

Average High and Low Temperature in August in Ko SamuiAug112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313178°F78°F80°F80°F82°F82°F84°F84°F86°F86°F88°F88°F90°F90°F92°F92°F94°F94°F96°F96°F98°F98°F100°F100°F102°F102°FJulSepAug 189°FAug 189°F80°F80°FAug 3189°FAug 3189°F80°F80°FAug 1189°FAug 1189°F80°F80°FAug 2189°FAug 2189°F80°F80°FNowNow
The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on August. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature in August in Ko Samui

Average Hourly Temperature in August in Ko SamuiAug112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313112 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMJulSepNowNowwarmwarmhot
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Cartagena, Colombia (11,036 miles away); Oranjestad, Aruba (10,776 miles); and Camocim, Brazil (9,717 miles) are the far-away foreign places with temperatures most similar to Ko Samui (view comparison).

Map
Marker
© Esri, et al.

Compare Ko Samui to another city:

Map

The month of August in Ko Samui experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 93% throughout the month. The highest chance of overcast or mostly cloudy conditions is 94% on August 10.

The clearest day of the month is August 31, with clear, mostly clear, or partly cloudy conditions 7% of the time.

For reference, on May 29, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 94%, while on February 9, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 47%.

Cloud Cover Categories in August in Ko Samui

Cloud Cover Categories in August in Ko SamuiAug11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JulSepFeb 947%Feb 947%Aug 17%Aug 17%Aug 317%Aug 317%Aug 116%Aug 116%Aug 216%Aug 216%NowNowmostly cloudyovercastpartly cloudy
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Ko Samui, the chance of a wet day over the course of August is rapidly increasing, starting the month at 47% and ending it at 54%.

For reference, the year's highest daily chance of a wet day is 64% on October 26, and its lowest chance is 9% on February 20.

Probability of Precipitation in August in Ko Samui

The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during August in Ko Samui is increasing, starting the month at 4.9 inches, when it rarely exceeds 7.6 inches or falls below 2.7 inches, and ending the month at 5.5 inches, when it rarely exceeds 8.0 inches or falls below 3.2 inches.

The lowest average 31-day accumulation is 4.9 inches on August 11.

Average Monthly Rainfall in August in Ko Samui

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average snowfall.

Over the course of August in Ko Samui, the length of the day is essentially constant. The shortest day of the month is August 31, with 12 hours, 18 minutes of daylight and the longest day is August 1, with 12 hours, 32 minutes of daylight.

Hours of Daylight and Twilight in August in Ko Samui

Hours of Daylight and Twilight in August in Ko SamuiAug11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hrJulSepnightnightdaydayAug 112 hr, 32 minAug 112 hr, 32 minAug 3112 hr, 18 minAug 3112 hr, 18 minNowNow
The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise of the month in Ko Samui is 6:10 AM on August 1 and the latest sunrise is 1 minute, 15 seconds later at 6:11 AM on August 20.

The latest sunset is 6:42 PM on August 1 and the earliest sunset is 13 minutes earlier at 6:29 PM on August 31.

Daylight saving time is not observed in Ko Samui during 2022.

For reference, on June 21, the longest day of the year, the Sun rises at 6:01 AM and sets 12 hours, 41 minutes later, at 6:42 PM, while on December 21, the shortest day of the year, it rises at 6:31 AM and sets 11 hours, 34 minutes later, at 6:05 PM.

Sunrise & Sunset with Twilight in August in Ko Samui

Sunrise & Sunset with Twilight in August in Ko SamuiAug11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031312 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJulSep6:10 AM6:10 AMAug 16:42 PMAug 16:42 PM6:11 AM6:11 AMAug 316:29 PMAug 316:29 PM6:11 AM6:11 AMAug 206:35 PMAug 206:35 PMSolarMidnightSolarMidnightSolarNoonSunriseSunsetNowNow
The solar day over the course of August. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray.

The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.

Solar Elevation and Azimuth in August in Ko Samui

Solar Elevation and Azimuth in August in Ko SamuiAug112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313112 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMJulSep0010102020203030404050505060607070800001010202030303040405050606060707080NowNow
northeastsouthwest
Solar elevation and azimuth over the course of August 2022. The black lines are lines of constant solar elevation (the angle of the sun above the horizon, in degrees). The background color fills indicate the azimuth (the compass bearing) of the sun. The lightly tinted areas at the boundaries of the cardinal compass points indicate the implied intermediate directions (northeast, southeast, southwest, and northwest).

The figure below presents a compact representation of key lunar data for August 2022. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.

Moon Rise, Set & Phases in August in Ko Samui

Moon Rise, Set & Phases in August in Ko SamuiAug112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313112 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMJulSepJul 141:38 AMJul 141:38 AMJul 2912:56 AMJul 2912:56 AMAug 128:36 AMAug 128:36 AMAug 273:18 PMAug 273:18 PMSep 105:00 PMSep 105:00 PMSep 264:55 AMSep 264:55 AM6:29 PM6:29 PM6:23 AM6:23 AM6:26 AM6:26 AM7:22 PM7:22 PM6:13 PM6:13 PM6:12 AM6:12 AM6:01 AM6:01 AM6:44 PM6:44 PM6:32 PM6:32 PM6:47 AM6:47 AM6:18 AM6:18 AM6:40 PM6:40 PMNowNow
The time in which the moon is above the horizon (light blue area), with new moons (dark gray lines) and full moons (blue lines) indicated. The shaded overlays indicate night and civil twilight.
Aug 2022IlluminationMoonriseMoonsetMoonriseMeridian PassingDistance
1
12%8:51 AME9:24 PMW-3:08 PMS245,508 mi
2
20%9:38 AME10:02 PMW-3:51 PMS243,101 mi
3
29%10:25 AME10:41 PMW-4:33 PMS240,385 mi
4
39%11:13 AME11:23 PMW-5:18 PMS237,412 mi
5
50%12:04 PMESE--6:05 PMS234,280 mi
6
62%-12:07 AMWSW12:59 PMESE6:57 PMS231,148 mi
7
73%-12:57 AMWSW1:59 PMESE7:55 PMS228,241 mi
8
83%-1:53 AMWSW3:03 PMESE8:58 PMS225,829 mi
9
91%-2:55 AMWSW4:08 PMESE10:04 PMS224,197 mi
10
97%-4:00 AMWSW5:13 PMESE11:11 PMS223,586 mi
11
99%-5:07 AMWSW6:13 PMESE--
12
100%-6:12 AMWSW7:08 PMESE12:13 AMS224,127 mi
13
99%-7:12 AMWSW7:57 PMESE1:11 AMS225,810 mi
14
96%-8:09 AMW8:43 PME2:03 AMS228,480 mi
15
90%-9:01 AMW9:25 PME2:52 AMS231,878 mi
16
82%-9:52 AMW10:06 PME3:38 AMS235,681 mi
17
73%-10:41 AMW10:47 PMENE4:23 AMS239,558 mi
18
63%-11:30 AMWNW11:29 PMENE5:07 AMN243,206 mi
19
50%-12:20 PMWNW-5:53 AMN246,381 mi
20
42%12:13 AMENE1:11 PMWNW-6:41 AMN248,907 mi
21
33%12:59 AMENE2:02 PMWNW-7:30 AMN250,681 mi
22
24%1:48 AMENE2:53 PMWNW-8:20 AMN251,671 mi
23
16%2:38 AMENE3:44 PMWNW-9:11 AMN251,906 mi
24
10%3:29 AMENE4:33 PMWNW-10:02 AMN251,467 mi
25
5%4:21 AMENE5:19 PMWNW-10:51 AMN250,465 mi
26
1%5:11 AMENE6:03 PMWNW-11:38 AMN249,025 mi
27
0%6:01 AMENE6:44 PMWNW-12:24 PMN247,267 mi
28
1%6:48 AMENE7:24 PMW-1:07 PMN245,293 mi
29
4%7:36 AME8:03 PMW-1:50 PMS243,182 mi
30
9%8:23 AME8:42 PMW-2:32 PMS240,985 mi
31
16%9:11 AME9:22 PMW-3:16 PMS238,733 mi

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The chance that a given day will be muggy in Ko Samui is essentially constant during August, remaining around 100% throughout.

For reference, on March 21, the muggiest day of the year, there are muggy conditions 100% of the time, while on February 4, the least muggy day of the year, there are muggy conditions 100% of the time.

Humidity Comfort Levels in August in Ko Samui

Humidity Comfort Levels in August in Ko SamuiAug11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%JulSepAug 16100%Aug 16100%Aug 1100%Aug 1100%Aug 31100%Aug 31100%NowNowmiserablemiserableoppressiveoppressive
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Ko Samui is essentially constant during August, remaining within 0.3 miles per hour of 11.3 miles per hour throughout.

For reference, on December 13, the windiest day of the year, the daily average wind speed is 12.3 miles per hour, while on April 19, the calmest day of the year, the daily average wind speed is 7.1 miles per hour.

The highest daily average wind speed during August is 11.7 miles per hour on August 13.

Average Wind Speed in August in Ko Samui

Average Wind Speed in August in Ko SamuiAug11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310 mph0 mph2 mph2 mph4 mph4 mph6 mph6 mph8 mph8 mph10 mph10 mph12 mph12 mph14 mph14 mph16 mph16 mphJulSepAug 1311.7 mphAug 1311.7 mphAug 3111.0 mphAug 3111.0 mphNowNow
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The hourly average wind direction in Ko Samui throughout August is predominantly from the west, with a peak proportion of 91% on August 16.

Wind Direction in August in Ko Samui

Wind Direction in August in Ko SamuiAug11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310%100%20%80%40%60%60%40%80%20%100%0%JulSepNowNowwesteastnorthsouth
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Ko Samui is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average surface water temperature in Ko Samui is essentially constant during August, remaining around 85°F throughout.

Average Water Temperature in August in Ko Samui

Average Water Temperature in August in Ko SamuiAug112233445566778899101011111212131314141515161617171818191920202121222223232424252526262727282829293030313182.5°F82.5°F83.0°F83.0°F83.5°F83.5°F84.0°F84.0°F84.5°F84.5°F85.0°F85.0°F85.5°F85.5°F86.0°F86.0°F86.5°F86.5°F87.0°F87.0°FJulSepAug 185°FAug 185°FAug 3185°FAug 3185°FAug 1185°FAug 1185°FAug 2185°FAug 2185°FNowNow
The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

Temperatures in Ko Samui are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.

Time Spent in Various Temperature Bands and the Growing Season in August in Ko Samui

Time Spent in Various Temperature Bands and the Growing Season in August in Ko SamuiAug11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JulSep100%Aug 16100%Aug 16100%Jul 3100%Jul 3NowNowwarmhot
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

The average accumulated growing degree days in Ko Samui are very rapidly increasing during August, increasing by 1,001°F, from 7,063°F to 8,064°F, over the course of the month.

Growing Degree Days in August in Ko Samui

The average growing degree days accumulated over the course of August, with 25th to 75th and 10th to 90th percentile bands.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy in Ko Samui is essentially constant during August, remaining around 3.9 kWh throughout.

Average Daily Incident Shortwave Solar Energy in August in Ko Samui

Average Daily Incident Shortwave Solar Energy in August in Ko SamuiAug11223344556677889910101111121213131414151516161717181819192020212122222323242425252626272728282929303031310.0 kWh0.0 kWh0.5 kWh0.5 kWh1.0 kWh1.0 kWh1.5 kWh1.5 kWh2.0 kWh2.0 kWh2.5 kWh2.5 kWh3.0 kWh3.0 kWh3.5 kWh3.5 kWh4.0 kWh4.0 kWh4.5 kWh4.5 kWh5.0 kWh5.0 kWh5.5 kWh5.5 kWh6.0 kWh6.0 kWhJulSepAug 13.9 kWhAug 13.9 kWhAug 313.9 kWhAug 313.9 kWhAug 163.9 kWhAug 163.9 kWhNowNow
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

For the purposes of this report, the geographical coordinates of Ko Samui are 9.536 deg latitude, 99.936 deg longitude, and 26 ft elevation.

The topography within 2 miles of Ko Samui contains very significant variations in elevation, with a maximum elevation change of 1,509 feet and an average elevation above sea level of 171 feet. Within 10 miles contains very significant variations in elevation (2,067 feet). Within 50 miles contains large variations in elevation (4,518 feet).

The area within 2 miles of Ko Samui is covered by water (51%) and cropland (47%), within 10 miles by water (72%) and cropland (27%), and within 50 miles by water (85%).

This report illustrates the typical weather in Ko Samui, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Ko Samui.

For each station, the records are corrected for the elevation difference between that station and Ko Samui according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Ko Samui is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Ko Samui and a given station.

The stations contributing to this reconstruction are:

  • Koh Samui Airport (VTSM, 89%, 9 mi, east, 36 ft elevation change)
  • Surat Thani Airport (VTSB, 4.7%, 61 mi, southwest, -7 ft elevation change)
  • Nakhon Si Thammarat Airport (VTSF, 4.0%, 69 mi, south, -13 ft elevation change)
  • Chumphon Airport (VTSE, 2.6%, 90 mi, northwest, -10 ft elevation change)

To get a sense of how much these sources agree with each other, you can view a comparison of Ko Samui and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data.

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for airports and weather stations are provided by AskGeo.com .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.

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