Ko Samui surfForecast / Gulf of Thailand / Thailand

information circle12 Day Weather and Surf, issued 6 am Tuesday 16 Sep 2025 +07
Forecast update in hr  min  s Forecast update imminent
Ko Samui surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Ko Samui sea temperature is
29.5° C
(Which is slightly warmer than usual)


Best Forecast Surf Conditions for Ko Samui this week:

The most powerful waves expected at Ko Samui in the next 12 days are 0.3m 5s and forecast to arrive on Tuesday (Sep 16) at 10AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.4m 2s period and expected on Wednesday (Sep 17) at 7PM.

Wave TypeTime (+07) & Date Wave Height & Period
Next good surf (1 star+)--
Best Surf--
Most Powerful10AM (Tue 16th Sep)1ft (0.3m) 5s

Table - best surf conditions forecast for Ko Samui over the next 12 days.

Updates in  hr  min  s Forecast update imminent

Short Range Forecast Moderate rain (total 10mm), heaviest on Thu afternoon. Warm (max 30°C on Wed afternoon, min 26°C on Thu night). Winds increasing (light winds from the NW on Wed afternoon, strong winds from the WSW by Thu night).

Days 3-6 Weather Summary Light rain (total 3mm), mostly falling on Sun night. Warm (max 31°C on Sat afternoon, min 27°C on Fri morning). Winds decreasing (fresh winds from the W on Sat afternoon, calm by Sun afternoon).

Tuesday
16
Wednesday
17
Thursday
18
Friday
19
Saturday
20
Sunday
21
Monday
22
AMPMNightAMPMNightAMPMNightAMPMNightAMPMNightAMPMNightAMPMNight
Rating
(10 max)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Swell
Height Map
Wave Height (m) & direction (?)
0.3
SE
0.3
SE
0.1
SE
0.1
SE
0.1
E
0.1
SE
0.1
SE
0.1
SE
0.3
W
0.1
SE
0.3
WNW
0.4
SW
0.1
E
0.3
SSE
0.1
SE
0.1
SE
0.4
SE
0.1
E
0.2
ESE
0.2
ESE
0.1
SE
Period(s) (?)565576552523655546554
Wave
Graph
(?)Metric surfscale
Energy (?)551122110200241151321
Wind
(km/h)
20
WSW
20
SW
25
WSW
25
WSW
15
NW
30
WSW
25
W
20
W
30
W
35
W
30
W
30
WSW
30
WSW
35
W
30
WSW
20
WSW
5
SE
15
SW
20
WSW
5
NNE
25
WSW
Wind State (?)
onshore
cross-onshore
cross-shore
cross-offshore
offshore
glassy
cross-
off
cross-
off
cross-
off
cross-
off
offcross-
off
cross-
off
offcross-
off
cross-
off
cross-
off
cross-
off
cross-
off
cross-
off
cross-
off
cross-
off
oncross-
off
cross-
off
crosscross-
off
High Tide
/ height (m)
5:35PM
1.35
6:38PM
1.30
7:42PM
1.24
8:43PM
1.15
9:39PM
1.06
10:32PM
0.94
12:25PM
0.64
11:25PM
0.82
Low Tide
/ height (m)
6:07AM
0.09
6:38AM
0.12
6:52AM
0.19
6:51AM
0.27
6:42AM
0.36
6:28AM
0.44
4:55PM
0.57
Tuesday
16
Wednesday
17
Thursday
18
Friday
19
Saturday
20
Sunday
21
Monday
22
Sunrise6:09--6:09--6:09--6:09--6:09--6:09--6:09--
Sunset-6:20--6:19--6:17--6:17--6:16--6:15--6:15-
part cloud
thunderstorm
part cloud
part cloud
thunderstorm
part cloud
part cloud
thunderstorm
thunderstorm
cloud
part cloud
part cloud
clear
part cloud
clear
part cloud
thunderstorm
thunderstorm
clear
part cloud
part cloud
Rain (mm)
-1--1--35-------12---
Temp. °C282929283029282927272828293129293029292930
Feels °C (?)293029283029292726252727272829293432293232
  • Map Icons:
  • Break
  • Live Wave Height (m)
  • Live Wind Speed (km/h)
  • Surf Rating (10 Max)
  • Ocean Swells (m)
  • Wind Speed (km/h)
Map placeholder

Eyeball surf reportRecent Eyeball Surf Reports for Gulf of Thailand

  1. weather stationWind Update Continuing clean conditions at Ko Samui (calm at Samui Airport 4 km from Ko Samui). 0.2m 4s local chop from the SSE with a 0.2m 6s windswell from the SE. 2 swells combining to make bigger set waves.

    Ko Samui
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2 h 24 min ago

0 km/h
N
Clean
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FREE! Surf-Forecast.com widget for your website

The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Ko Samui surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.


Information about the Ko Samui Surf forecast

The above surf forecast table for Ko Samui provides essential information for determining whether the surfing conditions will be good over the next 12 days. A general guide to surfing at Ko Samui can be found by selecting the local surf guide option on the grey menu. Our Ko Samui surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Ko Samui) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).

Further information to help with frequently asked questions about our surf forecast for Ko Samui may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.

Ko Samui is 14 km (9 miles) from the city of Ko Samui. If you plan a holiday in Gulf of Thailand, look for hotels and other accommodation in Ko Samui. Ko Samui has rooms for a wide range of budgets as well as car hire and transport links.

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