Koh Samui, Thailand
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Koh Samui

January beach and weather guide

Based on 5 years of historical ERA5 climate data

Photo by Marius Kriz on Unsplash

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January beach conditions — historical average

Good
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📈 Our data shows more favourable conditions in 2024-2025 compared to 2021-2022 for this destination and time of year
25.6°C Temp
28.7°C Sea temp
6.4 Rain days
10.7h Sunshine hrs
77.0% Humidity
80%

Reliable conditions

4 of 5 years were good

Year by year — mid January

2025 Good 25.5°C · 5 rainy days · 10.7h sun
2024 Excellent 27.1°C · 7 rainy days · 10.9h sun
2023 Excellent 25.8°C · 4 rainy days · 10.4h sun
2022 Good 25.5°C · 6 rainy days · 11.0h sun
2021 Good 24.3°C · 10 rainy days · 10.5h sun

Other months in Koh Samui

January February March July August September

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Each trip type is scored on what matters most for it — snow days for skiing, sea temp for beach, sunshine for sightseeing.

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About Koh Samui in January

Based on 5 years of ERA5 historical climate data, January in Koh Samui has historically been good for a beach holiday. Average temperatures of 25.6°C with sea temperatures around 28.7°C and 6.4 rainy days on average.

4 of the last 5 years had good beach conditions during this period. This data uses ERA5 reanalysis records — real historical measurements, not generalised averages.

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