Thailand in September
In short
Thailand in September is the wettest, quietest and cheapest month, but the Gulf islands still get beach days.
Why September works
Is September a good time to visit Thailand? For a group that wants clubs, villas and quiet beaches more than sun, yes. It's the wettest month in most of the country, but Koh Samui gets the least rain of the big resorts.
The upside is the price and the space: it's the cheapest month of the year, with the quietest beaches and temples. The downside is heavy rain in Bangkok and rough seas on the Andaman coast.
So the plan is a villa with a pool, Bangkok's clubs, and the Gulf for the beach. Ask Tanner to build the week around the pool.
How much it rains
Thailand in September weather is hot and wet: highs of 31 to 33°C almost everywhere, and the rain comes in heavy bursts.
Bangkok averages about 336 mm over 18 rain days, while Koh Samui gets about 118 mm over 11, on the 1991–2020 normals.
Hua Hin is one of the drier coastal spots, and Koh Chang is the wettest, with rain on most days. Ask Tanner for a Hua Hin weekend.
Bangkok
- Rain:
- about 336 mm
- Rain days:
- 18
- What to expect:
- Heavy downpours; streets can flood briefly
Koh Samui
- Rain:
- about 118 mm
- Rain days:
- 11
- What to expect:
- The least rain of the big resorts
Hua Hin
- Rain:
- about 130 mm
- Rain days:
- 11
- What to expect:
- One of the drier coastal spots
Pattaya
- Rain:
- about 214 mm
- Rain days:
- 13
- What to expect:
- Wet; its roughest seas of the year
Phuket and the Andaman
- Rain:
- about 350 mm
- Rain days:
- 19
- What to expect:
- Rough seas, red flags on west-coast beaches
Chiang Mai
- Rain:
- about 207 mm
- Rain days:
- 15
- What to expect:
- Green and wet
Koh Chang
- Rain:
- about 816 mm
- Rain days:
- 22
- What to expect:
- The wettest; skip it this month
- 310 days to Wednesday 15 September
- The wettest month in most of Thailand
- Koh Samui, then Hua Hin
- Wednesday 15 September 2027
- None in September 2027
What's on in September 2027
September 2027 is quiet: the Bank of Thailand's 2027 holiday notice lists no holidays in the month. The Full Moon Party is the one big date, on Wednesday 15 September on the party schedules.
A Buddhist holiday can move the party, so reconfirm the date before you book the boat.
In 2027 the Phuket Vegetarian Festival starts at the very end of September, on 30 September, Phuket City Municipality says.
See the Thailand party calendar and Thailand public holidays. Ask Tanner what lines up with your dates.
Wednesday 15 September
- Event:
- Full Moon Party
- Where:
- Haad Rin, Koh Phangan
Wednesday 13 October
- Event:
- The Passing of King Bhumibol (public holiday)
- Where:
- Nationwide
Saturday 16 October
- Event:
- Full Moon Party
- Where:
- Haad Rin, Koh Phangan
Saturday 23 October (Monday 25 off)
- Event:
- Chulalongkorn Day (public holiday)
- Where:
- Nationwide
What to book first
Almost nothing sells out in September, so you rarely need to book far ahead.
The one exception is the Full Moon week. Villas near Haad Rin go first, then Koh Samui villas, because the Gulf has the least rain. Bangkok clubs, Pattaya villas and Hua Hin are easy.
Ask Tanner to hold the Full Moon week first.
Where to take the group
Where to go in Thailand in September? Koh Samui and Koh Phangan for the Full Moon, Hua Hin for the beach, and Bangkok for the clubs.
Bangkok has the rooftops and the big clubs, and licensed venues in its three late zones (Silom, RCA and Ratchada) may open until 4am, TAT News says.
Pattaya is two hours from Bangkok, with pool villas from ฿12,500 a day. In Phuket, take a villa with a pool, from ฿18,500 a day, and skip the boats: Maya Bay is closed until 30 September every year.
See Hua Hin nightlife and Koh Samui to Koh Phangan. Ask Tanner for the car to Hua Hin.
AIPlanning around the rain
Plan a September trip with a pool villa as the base and the clubs after dark, and keep the beach and the boats flexible, so a wet day never costs you the trip.
The villa is your own pool, with a DJ and the bar poured. The clubs are Bangkok's big rooms and covered rooftops.
Take the boat on the Gulf only, on a calm morning: a motor yacht, priced by the boat and quoted to your plan, with the party layer on top. And with your own car, nobody waits for a ride in the rain.
Plan it with Tanner, and the boat waits for the first calm morning.
Is Thailand better in September or October?
October is a touch drier on the Andaman side, but it starts the Gulf islands' own rainy season, which peaks in November. September is the Gulf's last good month before that.
Pick September for the Gulf islands and the Full Moon on 15 September. Pick October for the Andaman coast as it starts to dry, and the Full Moon on Saturday 16 October.
See Thailand in August for the month before and Thailand in October for the month after. Ask Tanner which month suits your group.
What ten of you really spend
Ten friends, three days in a Koh Samui pool villa, the boat to Haad Rin on Koh Phangan for the Full Moon, a DJ for the pool day and the bar poured.
Tanner's pick: September? Base the group on Koh Samui, and take the boat to Haad Rin for the Full Moon. Ask Tanner for the Samui villa.
Pool villa, 3 days
- For ten:
- From ฿55,500
DJ for the day
- For ten:
- ฿8,000
Open bar for 10
- For ten:
- ฿15,000
All in
- For ten:
- About ฿78,500
What to pack for September
Thailand in September is warm and wet, so pack light: quick-dry clothes, sandals, a light rain jacket or a compact umbrella, and a dry bag for the boat.
Insider tip: Bangkok streets can flood briefly after a downpour, so keep the car close and save the club shoes for the door.
See our Thailand packing list, and ask Tanner what the club dress codes need.
Thailand in September in short
Weather: the wettest month in most of Thailand; Bangkok about 336 mm.
Best beaches: Koh Samui (about 118 mm), then Hua Hin.
Avoid: Andaman boat days and Koh Chang.
Public holidays: none in September 2027.
Full Moon: Wednesday 15 September 2027.
Book: the cheapest month; villas are easy.
Checked October 2026 for Thailand, September 2027.
Ask Tanner for a September price today.
Tanner's offer
Your September week on one plan: the villa, the Full Moon and the cars.
Plan it with Tanner →
Written by Tanner Altman · Updated 7 November 2026
Questions
Questions about Thailand in September
Is September a good time to visit Thailand?
For a quiet, cheap trip, yes. It's the wettest month, so base the trip on a pool villa and Bangkok's clubs, and use Koh Samui and Hua Hin for the beach.
What is the wettest month in Thailand?
September, in most of the country. Bangkok averages about 336 mm over 18 rain days on the 1991–2020 normals.
Which Thai beach is best in September?
Koh Samui, with about 118 mm of rain over 11 days, the least of the big resorts. Hua Hin is one of the drier coastal spots too.
Is Phuket worth visiting in September?
Only for the villa and the pool. It's about 350 mm over 19 days, with rough seas and red flags on the west-coast beaches, and Maya Bay stays closed until 30 September.
Are there public holidays in September 2027?
Office Holidays lists none. The next one is The Passing of King Bhumibol on Wednesday 13 October. Ask Tanner to check ban days for your exact dates.
When is the Full Moon Party in September 2027?
Wednesday 15 September 2027, on the party schedules. A Buddhist holiday can move the date, so reconfirm before you book.
What is the weather like in Thailand in September?
Hot and wet: highs of 31 to 33°C, heavy downpours in Bangkok, and the least rain on Koh Samui, about 118 mm over 11 days.
Is September cheap in Thailand?
Yes. It's the month with the lowest prices of the year, cheapest of all on the Andaman coast, and you rarely need to book far ahead.
Where should we go in Thailand in September?
Koh Samui and Koh Phangan for the Full Moon, Hua Hin for the beach, and Bangkok for the clubs. Skip the Andaman boat days.
Plan it
Plan it with Tanner
Are you in Thailand now?
Sources
- TAT News: Entertainment venues in Thai tourist destinations to open until 4 am (15 Dec 2023: set zones of Bangkok, Phuket, Chon Buri, Chiang Mai and Ko Samui; licensed hotels nationwide), checked October 2026
- Visit Thailand Today: Thailand in September (1991–2020 normals), updated 2 Oct 2026, checked 29 Oct 2026
- Thaiest: Full Moon Party schedule (15 Sep and 16 Oct 2027), updated 27 Oct 2026
- Office Holidays: Thailand 2027 (none in September; 13 Oct, 25 Oct)
- Bank of Thailand: Notification No. 37/2569, 2027 bank holidays, checked November 2026
- Phuket City Municipality: Phuket Vegetarian Festival 2027, 30 September to 8 October, checked 2 November 2026
Credits: top photo AI-generated image.