When to Visit Koh Samui
Climate guide & best times to travel
Best Time to Visit
Month-by-Month Guide
January
January marks the tail end of the wet season with moderate rainfall of 5.0 inches. Temperatures are at their coolest for the year with comfortable highs of 84°F and lows of 75°F. Occasional showers and overcast skies are common, but plenty of sunny periods allow for beach activities.
February
February is Samui's driest month with only 2.5 inches of rainfall, making it ideal for all outdoor activities. Temperatures remain pleasant at 84°F highs and 76°F lows with abundant sunshine. This is one of the most popular months for visitors seeking guaranteed good weather.
March
March brings slightly warmer temperatures with highs of 86°F and continues the dry season trend with 4.6 inches of rainfall. The weather is excellent for beach activities, water sports, and exploring the island. Humidity remains comfortable at 70% with mostly sunny skies.
April
April sees temperatures climbing to 89°F with relatively low rainfall at 3.3 inches. The hot, dry conditions make it perfect for beach lovers and water activities. This marks the beginning of the hotter season, but sea breezes help keep coastal areas comfortable.
May
May brings the year's highest temperatures with 91°F highs and increased rainfall at 5.2 inches. Despite the heat and occasional afternoon showers, it's still a good time for beach activities. The rain often comes in short, intense bursts followed by clear skies.
June
June maintains hot temperatures at 90°F with moderate rainfall of 5.3 inches. The weather pattern typically features sunny mornings and possible afternoon thunderstorms. Despite the rain, this month offers good value for travelers and decent beach weather between showers.
July
July continues the hot season with 90°F highs and 4.6 inches of rainfall. Weather conditions are generally favorable with a mix of sunny and partly cloudy days. The southwest monsoon has minimal impact on Samui, making it a reliable month for vacation planning.
August
August offers some of the most stable weather with 90°F temperatures and moderate 4.0 inches of rainfall. Conditions are ideal for most activities with predominantly sunny skies and brief, refreshing showers. The sea remains calm and perfect for swimming and water sports.
September
September begins the transition toward the wet season with 89°F temperatures and 4.6 inches of rainfall. Weather remains generally good for tourism with mostly sunny days and occasional tropical showers. This is often considered one of the last reliable months before heavier rains arrive.
October
October marks the beginning of the wet season with significantly increased rainfall at 11.6 inches and cooler temperatures of 87°F. Expect frequent showers, overcast skies, and possible storms, though temperatures remain warm. Beach activities are still possible between rain periods.
November
November is the wettest month with 17.5 inches of rainfall and temperatures dropping to 85°F. Heavy downpours, thunderstorms, and overcast conditions are common, making outdoor activities challenging. However, accommodation rates are at their lowest, and the island maintains its lush, tropical beauty.
December
December continues the wet season with 10.4 inches of rainfall, though conditions begin to improve compared to November. Temperatures remain pleasant at 84°F with a mix of rainy and partly sunny days. The latter half of the month often sees improving weather as the dry season approaches.