Ayutthaya weather in September
September in Ayutthaya: sweltering, soaked, with muggy air — not the time — 26 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#12 of 12 months in Ayutthaya · #1305 of 1413 destinations to visit in September · comfort 44/100 (tier F)
- Days
- 33°C
- Nights
- 25°C
- Wet days
- 26
- Sun
- 8.1 h
- Humidity
- 83%
- Daylight
- 12 h
Traveller notes on Ayutthaya in September
Other months in Ayutthaya
Thailand's forum is consistent that June sits in a relative lull between the wetter bookends of May and September - it's still hot and humid nationwide, and Ayutthaya specifically gets called out as brutal around midday, but the rain itself is usually a shower rather than an all-day event. Forum regulars who visited Ayutthaya in June had a genuinely good time, describing it as hot and humid with manageable showers rather than a washout. The advice that comes up again and again is to tour the temple ruins early in the morning and save the hottest hours for indoor breaks.
Forum posters describe December as highly predictable and among the most pleasant months across central Thailand generally, with hot daytime temperatures (commonly reaching into the low 30sC), clear skies and minimal rain, while evenings cool into the low-20s or even high-teensC - genuinely comfortable by regional standards. This makes December squarely inside Thailand's cool, dry high season, good conditions for exploring Ayutthaya's outdoor temple ruins on foot without the wet-season rain risk. The clear tradeoff posters note for the broader region this time of year: December is also peak tourist season, so popular sites and accommodations get busy and should be booked ahead.
Add your own note from Ayutthaya's card on the map.
Ayutthaya climate normals — September
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Ayutthaya in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Quietschool holidays in 3 of the markets that fill it, one of its worst months for weather(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Ayutthaya's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Toughest weatherAyutthaya's weather peaks December–February.
September coincides with Flood season on the rivers.
Best weatherFair weatherToughest weather
What's on in Ayutthaya in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Flood season on the rivers
1 Sep – 15 Nov · usuallyClosuresDischarge from the Chao Phraya dam upstream backs into the low districts around the island most years, closing riverside roads and some outlying temples for days at a time. Source ↗
- Season
Wet season
MonsoonRisk26 rainy days and about 279 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of Ayutthaya — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Ayutthaya?
Ayutthaya in September — FAQ
- Is September a good time to visit Ayutthaya?
- September in Ayutthaya: sweltering, soaked, with muggy air — not the time — 26 rainy days. It ranks #12 of 12 months for Ayutthaya on SeasonMap's comfort score (44/100).
- What is the weather like in Ayutthaya in September?
- In September, Ayutthaya averages a daily high of 32.9°C and a low of 24.5°C, with about 278.5 mm of rain over roughly 26.4 rainy days.
- What is the air quality in Ayutthaya in September?
- Ayutthaya has a mean US Air Quality Index of about 62 in September.
Within 300 km: Bangkok's Dry days on Buddhist holy days on 1 Jan – 31 Dec, and Pattaya's Southwest monsoon around 15 May – 31 Oct.