Located just 14 degrees north of the Equator, Bangkok is warm at any time of the year with temperatures over 30°C.
The most pleasant time to visit is the cool season that lasts from November till February.
March and April represent the hot season, and hot it is — 35°C on average, but don’t be surprised to see temperatures rising towards 40 degrees Celsius (around 100°F+).
This is the worst season to visit Bangkok, so plan a lot of air-conditioned shopping mall visits and get a hotel with a swimming pool.
Then there’s the wet season that runs from May till October. Expect massive downpours resulting in floods all over the city, and spells of thunder at times.
Extreme rainfall happens in September and October, so these months are best avoided.
Whatever season you’re visiting, don’t take the weather lightly — temple-tramping in the scorching afternoon sun can be a challenge, so come well-prepared.