Covers Phuket, Koh Samui, Koh Lanta, Koh Phi Phi, Bali, Palawan, the Maldives, Mauritius, the Seychelles and Zanzibar, with visa and park rules checked at the source.
UpdatedThis page carries dated prices, schedules or seasonal facts checked on the date above, and that window has now passed. Re-check the sources at the foot of the page before you book.
If your Thailand trip falls in July, the coast matters more than the island. The Andaman side, with Phuket, Phi Phi and Koh Lanta, is in the southwest monsoon: more rain, rough seas on west-facing beaches and boat trips that cancel at short notice. Koh Samui, in the Gulf of Thailand, is largely sheltered from it.
Samui wins at 7.68 out of 10, with 87°F (31°C) highs, an 87°F (31°C) sea and 3.9 inches (98 mm) of rain, about half of Phuket's July total. The upside of the Andaman side in July is price: Phuket's 4-star rooms are the cheapest of the year. The cards below show the order.
Score = 55% this month's weather + 45% the island's other five factors. How we score
| # | Island | Score | High °F | Sea °F | Rain (in) |
|---|---|---|---|---|---|
| 1 | Koh Samui | 7.7 | 87 | 87 | 3.9 |
| 2 | Phuket | 6.9 | 85 | 86 | 7.7 |
| 3 | Koh Lanta | 6.5 | 86 | 87 | 8.3 |
| 4 | Koh Phi Phi | 6.2 | 85 | 86 | 7.7 |
1Samui wins July by more than three-quarters of a point. Its weather score is 8.8, with 87°F highs, an 87°F sea and 3.9 inches of rain, while the Andaman islands sit in the monsoon. Chaweng and Lamai are calm and sandy now, and Choeng Mon is the easy bay for small children. A well-reviewed Chaweng 4-star cost $58 for July 14, 2027. Ang Thong National Marine Park, 44 islands to the west, is the classic boat day.
2Phuket is second, held up by its year-round strengths rather than its weather. July brings 7.7 inches of rain and monsoon swell onto the west coast, a 7.0 weather score, with 85°F highs and an 86°F sea. In return, the cheapest well-reviewed Patong 4-star was $32, less than half its January price. Teens can surf; families should stick to flagged beaches and pools. Book Phi Phi trips with a spare day.
3Lanta is third. Its Krabi data shows 8.3 inches of July rain, the most of the four, and a 6.8 weather score, with 86°F highs and an 87°F sea. The southwest monsoon sends surf onto its west-coast beaches and cancels many of the boat trips that make up most of its things to do. What is left is price: 4-star rooms from $52 and 3-star from $8. Its own page says skip it from May to October.
4Phi Phi shares Phuket's July weather, a 7.0 with 7.7 inches of rain, 85°F highs and an 86°F sea, and ranks last on its lower scores for things to do and value. Crossings from Rassada Pier get rough, and Maya Bay closes on August 1. Rooms fall by more than half, to $86 for a well-reviewed 4-star on July 14, 2027. If you go, go early in the month and stay a single night.
In this guide
Each island's July score is 55% its July weather score and 45% its year-round score for beaches, things to do, access, value and crowds. Islands our pages rate as worth it only for some travelers lose 0.4 points; Lanta and Phi Phi are both in that group because of exactly this season. The method is on how we score islands. Our weather data is read at gateway airports, so Phi Phi shares Phuket's numbers and Lanta uses Krabi's.
The Thai Meteorological Department dates the southwest monsoon from about mid-May. It blows straight onto the Andaman coast, where rain peaks in September and the season eases around mid-October. That is why Phuket's July weather score is 7.0 and Samui's is 8.8.
Samui's turn comes later. The northeast monsoon brings the Gulf coast its heaviest rain from about mid-October to early December. So the two coasts trade places twice a year. In our data Samui has the better weather from February to October and ranks first from March to October; Phuket takes over from November. See October for the changeover month and December for the Andaman high season.
July is not a washout in Phuket. Its island page describes showers most afternoons rather than all-day rain, and the sea is a warm 86°F (30°C). But the west-coast beaches, Patong, Karon, Kata and Kamala, take the swell directly. Red flags mean rip currents, and this is not the month for weak swimmers there. Teens can take surf lessons, which run in the monsoon months.
Boats are the bigger problem. Phi Phi crossings get rough, Lanta's island-hopping trips often do not run, and Maya Bay closes from August 1 to September 30. If Phi Phi matters to you, go in July rather than August, and keep a spare day in case your boat is cancelled.
Cheapest well-reviewed hotel rated 4 stars or better on Kayak for Wednesday, July 14, 2027, taxes and fees in, checked October 20, 2026:
| Island (area) | July 14, 2027 | January 13, 2027 |
|---|---|---|
| Koh Samui (Chaweng) | $58 | $84 |
| Phuket (Patong) | $32 | $76 |
| Koh Lanta (west coast) | $52 | $84 |
| Koh Phi Phi (Tonsai) | $86 | $187 |
Samui is the only one of the four that is in good weather now, and it still costs $26 a night more than Phuket. For bare-bones budgets, Lanta's cheapest 3-star room was $8. See our cheap islands ranking for more.
No US airport flies nonstop to Samui. The usual route is a long-haul flight to Bangkok, then about an hour on Bangkok Airways, which owns Samui's airport. Scoot flies from Singapore. The cheaper, slower option is to fly to Surat Thani and take the ferry from Don Sak to Samui's piers.
Since September 15, 2026, US citizens get 30 days visa-free in Thailand, down from 60, with up to 30 more by application. File the free Thailand Digital Arrival Card within 72 hours before arrival. More in our passport rules guide. For other July options, including Bali in its driest months, see the world July ranking.
Transfers from the main beaches, lunch and entrance fees are included.
Rating as shown on GetYourGuide
Lunch and snorkel gear are included; the national park fee is only included if you pick that option. Expect a crowded, fast day; Maya Bay closes for August and September.
Rating as shown on GetYourGuide
Pickup, guide, kayak and lunch are included; calm water, good for beginners.
Rating as shown on GetYourGuide
Booking through these links supports this site at no cost to you. Prices move by date, so we do not print them here; the official prices we checked are in the page above.
Koh Samui. It is on the Gulf coast, out of the main path of the southwest monsoon, and gets about 3.9 inches of rain in July in our data against 7.7 in Phuket.
It is the low season, not a lost one. Expect showers, rough water on west-coast beaches and some cancelled boat trips. In return, a well-reviewed Patong 4-star cost $32 on July 14, 2027, against $76 in January.
Yes, until July 31. It closes every year from August 1 to September 30 for recovery, and crossings from Phuket can be cancelled in rough weather during the monsoon.
We have no monthly figure. Over 2025 Samui counted 3.3 million overnight tourists, about a quarter of Phuket's total, so even in its good season it is the smaller crowd of the two.
Only if price matters more than beach time. Rooms are at their cheapest, but its data shows 8.3 inches of July rain, and many boat trips do not run from May to October.
Further reading
