Phuket or Koh Samui? Two big islands, two different rainy seasons.
The short answer: Phuket, on the Andaman Sea, is Thailand's largest island: more beaches, more hotels, many more flights and the big nightlife of Patong. Koh Samui, in the Gulf of Thailand, is less than half the size, with a smaller airport, a ring road around the island and a calmer feel outside Chaweng. The biggest difference is the weather: their wettest months fall at different times of year, so the month you travel often decides it.
Below: a side-by-side comparison, rain month by month, who each island suits, and how to travel between them.
Phuket and Koh Samui side by side
The practical differences that usually decide it. Checked in November 2026.
| Phuket | Koh Samui | |
|---|---|---|
| Size | About 543 km², Thailand's largest island, joined to the mainland by a bridge | About 229 km², the second largest; a 51 km ring road goes round it |
| Flights | Phuket International Airport, with many nonstop routes, including long-haul | Samui Airport, owned by Bangkok Airways: Bangkok, a few Thai cities and a handful of international routes such as Singapore and Hong Kong |
| Rainiest months | About May to October, wettest in September and October | About October to December, wettest in November |
| Driest months | About December to March | About February to April; June to August also gets much less rain than Phuket |
| Beaches | A long west coast of separate beaches: Patong, Karon, Kata, Kamala, Bang Tao and more | Chaweng, Lamai, Bophut and Maenam, plus quieter bays in the south and west |
| Nightlife | Bangla Road in Patong and big beach clubs | Bars and clubs in Chaweng and Lamai, on a smaller scale |
| Day trips | Phi Phi, Phang Nga Bay and James Bond Island, the Similan Islands (mid-October to mid-May) | Ang Thong Marine Park (closed 1 November to about mid-December), Koh Phangan, Koh Tao, Pig Island |
Rain figures are long-term averages (1991–2020) from the Thai Meteorological Department stations in Phuket and on Koh Samui; see the month-by-month table below.
Which one should you pick?
Choose Phuket if you travel between about December and March, want lots of choice in one place (beaches, hotels, nightlife, attractions for children) or want the easiest flights from abroad.
Choose Koh Samui if you travel between about June and August, when the Andaman coast is in its rainy season and Samui is usually much drier, or if you want a smaller, quieter island with the Gulf islands of Koh Phangan and Koh Tao close by.
Avoid Samui in November if you can: it is the island's wettest month by far, and Ang Thong Marine Park is closed. In September and October, Phuket is at its wettest.
Rain month by month
Average rainfall per month and the number of rain days, 1991–2020, Thai Meteorological Department (WMO climate normals). A "rain day" means at least 1 mm of rain; many are short showers.
| Month | Phuket | Koh Samui |
|---|---|---|
| January | 50 mm 4 rain days |
127 mm 8 rain days |
| February | 24 mm 2 rain days |
64 mm 4 rain days |
| March | 81 mm 6 rain days |
116 mm 5 rain days |
| April | 135 mm 10 rain days |
83 mm 6 rain days |
| May | 237 mm 16 rain days |
132 mm 11 rain days |
| June | 249 mm 16 rain days |
134 mm 10 rain days |
| July | 240 mm 16 rain days |
117 mm 11 rain days |
| August | 309 mm 17 rain days |
102 mm 10 rain days |
| September | 350 mm 19 rain days |
118 mm 11 rain days |
| October | 336 mm 19 rain days |
295 mm 16 rain days |
| November | 178 mm 13 rain days |
445 mm 16 rain days |
| December | 82 mm 8 rain days |
263 mm 12 rain days |
More months and places on our Thailand climate guide.
Size and atmosphere
Phuket is more than twice the size of Samui and much busier, with more hotels, more traffic and the late-night scene of Patong. Its beaches are spread along the west coast, so where you stay matters; see where to stay in Phuket.
Samui is smaller and easier to get your bearings on: one road runs round the island, about 51 km. Chaweng is the busiest beach, Lamai is a little calmer, and Bophut and Maenam on the north coast are quieter. See where to stay on Koh Samui.
Weather
This is usually the deciding point. Phuket is on the Andaman coast, which gets most of its rain from about May to October. Samui is in the Gulf of Thailand, where the heaviest rain comes later, from about October to December, with November the wettest month of the year.
So in July or August, Samui is often the better bet; in November and December, Phuket is. Both are hot all year, and even in the rainy months many days have sunshine between showers.
Getting there
Phuket International Airport has far more nonstop routes, including long-haul flights, so it is usually the simpler way in from abroad. See Bangkok to Phuket.
Samui Airport is privately owned by Bangkok Airways, which flies most routes there, and fares tend to be higher than to Phuket. Besides Bangkok, there are flights from Phuket, Krabi and Chiang Mai and a handful of international routes, such as Singapore and Hong Kong. Many people fly to Surat Thani instead and take a bus and ferry. See Bangkok to Koh Samui.
Day trips
From Phuket the classic trips are Phi Phi and Maya Bay, James Bond Island and, from about mid-October to mid-May, the Similan Islands.
From Samui you can visit Ang Thong Marine Park (closed every year from 1 November to about mid-December), Pig Island, or take the boat to Koh Phangan and Koh Tao. See Koh Samui vs Koh Phangan.
Travelling between Phuket and Koh Samui
The two islands are on opposite coasts, so there is no direct boat. Bangkok Airways flies nonstop between them several times a day, in about an hour.
Overland, buses and vans run from Phuket to Donsak pier near Surat Thani, then a ferry crosses to Samui. Door to door it takes about 6 to 10 hours, depending on the operator and connections.
See buses, ferries and flights from Phuket to Koh Samui on 12Go
Phuket vs Koh Samui FAQ
Is Phuket or Koh Samui better?
Neither is better in every way. Phuket has more beaches, more hotels and more flights; Samui is smaller and calmer. The month you travel often decides it, because their rainy seasons fall at different times.
Which is better in July and August, Phuket or Koh Samui?
Usually Koh Samui. On long-term averages, Samui gets roughly half as much rain as Phuket in July and about a third in August.
Which is better in November and December?
Usually Phuket. November is Samui's wettest month, while Phuket is coming out of its rainy season.
Is there a ferry from Phuket to Koh Samui?
Not directly. Take a bus or van to Donsak pier near Surat Thani and the ferry from there, about 6 to 10 hours in all, or fly with Bangkok Airways in about an hour.
Is Koh Samui smaller than Phuket?
Yes. Samui is about 229 km² and Phuket about 543 km², so Phuket is more than twice the size.
Last checked: 7 November 2026. Island sizes from Wikipedia (Phuket, Ko Samui); rain from the WMO 1991–2020 climate normals for the Phuket and Ko Samui stations (Thai Meteorological Department); Samui Airport routes from Aviability and AeroRoutes; Phuket–Samui flights from Bangkok Airways; overland times from 12Go and SiamTickets; Ang Thong closure from Thai National Parks; Similan season from our Similan Islands page.