When to go · Thailand
When to go to Ko Samui
When to go
What the averages say
On these averages, Ko Samui has a mean high between 18°C and 32°C and under 150 mm of rain in January to April and August.
- Wet months (150 mm of rain or more): May to July and September to December.
- Humid months (a high of 25°C or more with relative humidity of 70% or more): January to December.
- The warmest month is May (30°C) and the coolest January (27°C). The wettest is November (375 mm) and the driest February (38 mm); about 2,088 mm of rain falls in a year.
How these sentences are worded
Each sentence is written from the figures by fixed rules, and says no more than they do. Mild to warm: a mean daily high from 18°C up to 32°C. Hot: 32°C or more. Cool: 10°C up to 18°C. Cold: under 10°C. Dry: under 50 mm of rain in the month; wet: 150 mm or more. Humid: a high of 25°C or more with relative humidity of 70% or more. A month is described as good for going when it is mild to warm and not wet.
The model's grid cell here is mostly sea, so the daily high and low sit closer together than they do on land: afternoons ashore are usually warmer, and nights cooler.
The year at a glance
- Mild to warm and dry
- Mild to warm, humid or showery
- Hot
- Cool
- Wet
- Cold
- JanMild–warm, mixed
- FebMild–warm, mixed
- MarMild–warm, mixed
- AprMild–warm, mixed
- MayWet
- JunWet
- JulWet
- AugMild–warm, mixed
- SeptWet
- OctWet
- NovWet
- DecWet
Month by month
Every month in Ko Samui
| Month | High | Low | Rain | Humidity | Cloud | Sunlight (kWh/m²/day) | High in Dubai | What it is like |
|---|---|---|---|---|---|---|---|---|
| January | 27°C | 26°C | 135 mm | 80% | 60% | 4.6 | 23°C | Mild to warm, humid or showery |
| February | 28°C | 26°C | 38 mm | 79% | 46% | 5.6 | 24°C | Mild to warm, humid or showery |
| March | 29°C | 27°C | 114 mm | 78% | 49% | 5.9 | 27°C | Mild to warm, humid or showery |
| April | 30°C | 28°C | 90 mm | 77% | 65% | 5.8 | 31°C | Mild to warm, humid or showery |
| May | 30°C | 28°C | 170 mm | 78% | 86% | 5.2 | 35°C | Wet |
| June | 30°C | 28°C | 167 mm | 80% | 87% | 5 | 37°C | Wet |
| July | 29°C | 28°C | 166 mm | 80% | 89% | 4.9 | 39°C | Wet |
| August | 29°C | 27°C | 144 mm | 81% | 89% | 4.9 | 39°C | Mild to warm, humid or showery |
| September | 29°C | 27°C | 181 mm | 81% | 89% | 4.9 | 37°C | Wet |
| October | 28°C | 27°C | 246 mm | 81% | 86% | 4.4 | 34°C | Wet |
| November | 28°C | 27°C | 375 mm | 81% | 81% | 3.9 | 29°C | Wet |
| December | 28°C | 27°C | 262 mm | 80% | 76% | 3.8 | 25°C | Wet |
The Dubai column is Dubai's mean daily high, for comparison.
Modelled averages for an area about 50 km across, not a weather station's record: NASA POWER climatology, 2001–2020. These data were obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program.
When to go nearby
When to go nearby
- Phuket249 kmGood for going: December to April
- Alor Setar383 kmGood for going: January to March
- Sungai Petani437 kmGood for going: January to March
- Kota Kuala Muda442 kmGood for going: January to March
- Kota Bharu457 kmGood for going: February to April
- Samut Prakan457 kmGood for going: November to January
- George Town461 kmGood for going: January to March
- Bangkok473 kmGood for going: November and December
Plan it
Plan a trip to Ko Samui
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