Ko Samui weather in June

In June, Ko Samui sees average daytime highs of 29°C and overnight lows near 27°C, with 89 mm of rain across 18.8 wet days and about 12.5 hours of daylight. It is the 1st-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 6% of the time in June, and the air most often feels miserable.

Daylight stretches from about 12 h 30 min at the start of June to 12 h 36 min by month's end. Set against the rest of the year, June is Ko Samui's 11th-clearest and 7th-windiest month. For the whole year in context, see Ko Samui's year-round climate.

Daytime high
29°
1st warmest
Overnight low
27°
10th coldest
Rainfall
89 mm
18.8 wet days
Daylight
12 h 36 min
6:04 AM – 6:37 PM
Cloud cover
84%
11th clearest
Wind
17 km/h
7th windiest
Solar energy
5.52 kWh/m²
Travel score
3.9
out of 10

Ko Samui is city in Surat Thani province, Thailand.

Density
219/km²
people per km²
Founded
1956

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

Temperature in June

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical June day in Ko Samui reaches about 29°C in the afternoon and slips back to 27°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 30°C. Set against its neighbours, June runs on par with May and on par with July.

25°28°30°33°35°151015202530
Avg high (°C)Avg low (°C)
12927
22927
32927
42927
52927
62927
72927
82927
92927
102927
112927
122927
132927
142927
152927
162927
172927
182927
192927
202927
212927
222927
232927
242927
252927
262927
272927
282927
292927
302927

How June really feels in Ko Samui

Once humidity and wind are folded in, June averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in June is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Ko Samui weather by month

How June compares with the rest of the year at a glance. June is the 1st-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 26°769.411.56.7
Feb27° / 26°355.311.77.3
Mar28° / 27°888.411.96.4
Apr29° / 28°9511.712.25.3
May29° / 27°11621.212.43.8
Jun29° / 27°8918.812.53.9
Jul29° / 27°8418.412.54.2
Aug29° / 27°911812.34.3
Sep28° / 27°14022.812.13.9
Oct28° / 26°2862611.83.9
Nov28° / 26°28920.911.64.6
Dec27° / 26°14513.211.55.9

Cloud cover in June

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 6% of the time in June.

Beyond those clear spells, partly cloudy skies cover about 8% of June, with mostly cloudy or overcast conditions the remaining 86%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
11585
21486
31585
41585
51585
61684
71684
81684
91684
101684
111684
121585
131585
141585
151585
161585
171585
181486
191486
201486
211486
221486
231486
241387
251387
261387
271288
281288
291288
301288

Chance of precipitation in June

Any precipitation

Ko Samui gets around 89 mm of rain over 18.8 wet days in June. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 63% and peaks near 73% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202530
Rain chance (%)
173
273
372
472
571
670
770
869
968
1067
1166
1265
1364
1463
1562
1661
1760
1859
1959
2058
2158
2257
2357
2456
2556
2656
2755
2855
2956
3056

Humidity in June

DryComfortableHumidMuggyOppressiveMiserable

Most of June feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, June lands in the miserable band about 76% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
11486
21585
31585
41585
51585
61585
71585
81684
91684
101783
111783
121882
131981
142080
152179
162278
172377
182476
192575
202773
212872
223070
233268
243466
253565
263763
273961
284060
294159
304258

Wind in June

Winds average 17 km/h in June.

Across June, daily wind ranges from about 16 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1317light breeze
1417light breeze
1517light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2018light breeze
2118light breeze
2218light breeze
2318light breeze
2418light breeze
2518light breeze
2618light breeze
2718light breeze
2818light breeze
2918light breeze
3018light breeze

Sunrise & sunset in June

DaylightNight

Daylight runs from about 12 h 30 min at the start of June to 12 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over June. Sunrise moves from 6:02 AM to 6:07 AM, and sunset from 6:33 PM to 6:40 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.56:026:33
212.56:026:33
312.56:026:34
412.56:026:34
512.56:036:34
612.56:036:35
712.56:036:35
812.56:036:35
912.56:036:35
1012.56:036:36
1112.56:036:36
1212.56:036:36
1312.56:036:36
1412.66:046:37
1512.66:046:37
1612.66:046:37
1712.66:046:37
1812.66:046:38
1912.66:046:38
2012.66:056:38
2112.66:056:38
2212.66:056:38
2312.66:056:39
2412.66:056:39
2512.66:066:39
2612.66:066:39
2712.66:066:39
2812.66:066:40
2912.66:076:40
3012.66:076:40

Solar energy in June

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in June, about 5.52 kWh/m².

For context, solar energy here swings from a low near 4.49 kWh/m² to a high of 6.44 kWh/m² in April across the year — June's 5.52 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.7Bright
25.6Bright
35.6Bright
45.6Bright
55.6Bright
65.6Bright
75.6Bright
85.6Bright
95.5Bright
105.5Bright
115.5Bright
125.5Bright
135.5Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.5Bright
265.5Bright
275.5Bright
285.5Bright
295.5Bright
305.5Bright
Planning a trip in June

Hazard calendar for Ko Samui

In seasonPeak

In June, Ko Samui sits inside its cyclone season. The full year is below, with each hazard's peak months called out.

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

Ko Samui's rainy season runs September–December, when most of the year's rain falls.

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

Is June a good time to visit Ko Samui?

Our two travel scores rate June for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

3.9
Sightseeing
9th-best month of the year
5.2
Beach & pool
8th-best month of the year

June is a weaker month for outdoor sightseeing in Ko Samui.

What to pack for Ko Samui in June

From June's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In June, Ko Samui sees daytime highs around 29°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection. About 19 days see rain.

light clothesrain gearsun protection

Sea temperature near Ko Samui in June

The nearest coast averages about 30°C in June — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in May at about 30°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
May30Tropical
Jun30Tropical
Jul30Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Ko Samui in June

LowModerateHighVery highExtreme

Clear-sky midday UV in June peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ko Samui peaks around August 22 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 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 22UV 14Dec 18UV 10
UV index (midday)Level
Jan10Very high
Feb12Extreme
Mar13Extreme
Apr13Extreme
May13Extreme
Jun12Extreme
Jul11Extreme
Aug14Extreme
Sep13Extreme
Oct11Extreme
Nov10Extreme
Dec10Very high

Air quality in Ko Samui in June

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where June falls, not just the annual average.

Air quality in Ko Samui is worst in January — around 16 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodJan 2016 µg/m³Nov 1110 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb15Moderate
Mar13Moderate
Apr14Moderate
May13Moderate
Jun14Moderate
Jul15Moderate
Aug12Good
Sep12Good
Oct11Good
Nov10Good
Dec12Moderate
Location & terrain

Where is Ko Samui?

Ko Samui sits at 9.5°N, 99.9°E, 8 m above sea level, in Thailand. The nearest listed city is Ko Pha-ngan, 27 km away.

Ban Na SanLang SuanNakhon Si ThammaratPak Phanang

Topography around Ko Samui

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

Within 3 km, the terrain around Ko Samui has significant variations in elevation — a maximum elevation change of 476 m around an average of 56 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 629 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,358 m.

The land around Ko Samui is covered by trees (51%) and water (42%) within 3 km, water (72%) and trees (24%) within 16 km, and water (82%) within 80 km.

3 km
476 m
16 km
629 m
80 km
1,358 m
treesgrasslandartificial surfaceswater
June weather nearby: Ko Pha-ngan 27 km · Ko Tao 63 km · Surat Thani 79 km · Tha Kham 91 km · Ban Na San 103 km · Lang Suan 104 km · Nakhon Si Thammarat 123 km · Pak Phanang 135 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 Samui (9.5357°, 99.9357°, elevation 8 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).