Koh Samui in January
In January, Koh Samui averages 28°C (82°F) during the day and 25°C (76°F) at night, with frequent rain — about 24 days of the month see precipitation (113 mm total).
ShoulderConditions are warm and beach-friendly. Expect daily rain or showers, often in heavy bursts.
January offers comfortable temperatures in Koh Samui, with some rain to plan around.
How January compares to the rest of the year in Koh Samui
January is one of the coolest months in Koh Samui (11th of 12) and moderately rainy compared to the rest of the year (8th of 12). Daytime temperature runs 1°C below the annual average (29°C). January runs roughly the same as December (28°C) and warms a further 1°C into February (28°C).
January sunrise & sunset in Koh Samui
Times shown for Koh Samui local time (Asia/Bangkok), calculated for the 15th of January. They shift by a few minutes day to day across the month.
Photography light in Koh Samui — January
Golden-hour and blue-hour windows for the 15th of January, in Koh Samui's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — Koh Samui in January
Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on January's tier (Shoulder) and Koh Samui's popularity.
Crowds & pricing — January in Koh Samui
Koh Samui is in a shoulder season month — fewer crowds, slightly lower prices, and a calmer atmosphere than peak weeks. Most major sights stay open with normal hours, though a handful of seasonal restaurants or boat trips may run reduced schedules. Many regulars consider these months the best time to visit because you trade a small amount of weather reliability for a much more pleasant on-the-ground experience.
Sun & mosquito risk — January in Koh Samui
UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.
Sea temperature in Koh Samui — January
Across the year Koh Samui's sea swings from 28.6°C (January) to 32.1°C (May) — January sits at 28.6°C.
Koh Samui in other months
| Month | Avg high | Avg low | Rainfall | Rain days | Snow days |
|---|---|---|---|---|---|
| January | 28°C / 82°F | 25°C / 76°F | 113 mm | 24 | — |
| February | 28°C / 83°F | 25°C / 77°F | 33 mm | 17 | — |
| March | 30°C / 86°F | 26°C / 78°F | 32 mm | 17 | — |
| April | 31°C / 87°F | 27°C / 80°F | 107 mm | 23 | — |
| May | 31°C / 87°F | 27°C / 80°F | 130 mm | 29 | — |
| June | 30°C / 86°F | 27°C / 80°F | 96 mm | 27 | — |
| July | 30°C / 86°F | 26°C / 79°F | 115 mm | 28 | — |
| August | 30°C / 86°F | 26°C / 79°F | 94 mm | 28 | — |
| September | 29°C / 84°F | 26°C / 78°F | 172 mm | 29 | — |
| October | 28°C / 83°F | 25°C / 77°F | 234 mm | 31 | — |
| November | 28°C / 82°F | 25°C / 77°F | 274 mm | 29 | — |
| December | 28°C / 82°F | 25°C / 76°F | 182 mm | 24 | — |
Other cities with similar January weather
🌍 See the full ranked list of climate twins for Koh Samui in January →
Frequently asked questions
How hot is Koh Samui in January?
In January, Koh Samui averages a high of 28°C (82°F) and a low of 25°C (76°F) — generally warm.
Does it rain a lot in Koh Samui in January?
January is quite rainy in Koh Samui, with about 24 rainy days on average.
Is January a good time to visit Koh Samui?
January is warm but on the rainy side. It suits travelers who are comfortable with warm weather; check the month-by-month ranking to compare it against the rest of the year.
What should I pack for Koh Samui in January?
Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full January packing list for Koh Samui for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.