Plan trips with rain data: Bangkok, Phuket, Chiang Mai, Hua Hin, Pattaya — month by month
One page for planning a Thailand trip: 10-year monthly rainfall means for the 5 destinations people search most on rooozt — read with the same bands as the weather calendar in the search bar: under 50 mm/month = low rain (green), 50–150 = moderate (yellow), over 150 = heavy (red).
Bangkok — clearly dry late in the year, peaking in September
December's 19 mm and January's 23 mm are Bangkok's bone-dry window — full days of outdoor city walking without carrying an umbrella. The opposite pole is September at 297 mm, followed by October at 245 mm, when short evening storms make traffic especially brutal. Always pad your airport travel time in this period.
Phuket — driest in February, wettest in October
February's 34 mm is Phuket's only month inside the low-rain band. True high season runs December–March (140/78/34/62 mm) — and the rainy season stretches May–November, peaking in October at 290 mm.
Chiang Mai — the most extreme spread on this list
March at 9 mm versus August at 412 mm — a 45× difference. November–February (68/25/20/26 mm) is the main travel season, and while March–April rain is very low, check the PM2.5 situation near your travel date too (that's general knowledge about the northern smoke season, not something from the rain dataset).
Hua Hin — the mildest-rain beach town on the list
Prachuap Khiri Khan never touches 250 mm in any month of the year — the October peak is 232 mm and December's low is just 37 mm. Even mid-year July–August (146/126 mm) runs at nearly half the Andaman's levels, making Hua Hin the numbers' first-choice beach for the rainy season.
Pattaya — a scaled-down version of Bangkok's profile
Chonburi is clearly dry December–January (17/19 mm) and heaviest September–October (242/232 mm) — with June easing to 99 mm right in the middle of the rainy season, a small window many people don't know exists.
Frequently asked questions
- Should October be avoided across the whole country?
- October is the transition month with high rainfall in almost every region (Bangkok 245, Phuket 290, Hua Hin 232 mm), but "high" doesn't mean "all day" — Thai rain mostly comes in bursts. If you travel this month, pick stays with good indoor options and build more flexibility into your plan than usual.
Where the numbers come from: Every rainfall figure in this article is a 2016–2025 monthly mean from the ERA5 dataset (via the Open-Meteo Historical Weather API) at each province's coordinate — a 10-year statistic, not a forecast for your trip. Any single year can differ a lot from the mean. This is the same dataset the weather calendar in rooozt's search bar displays.