Weather and light
April is hot, often the hottest month of the year, with high humidity building toward the end. Light is excellent — long, warm afternoons that suit late ceremony start times around 4 to 5 pm.
Songkran
Thailand's Songkran festival runs 13–15 April. It's a national holiday with water celebrations across the country. It rarely disrupts a private ceremony at a villa or resort, but it is worth planning transport carefully and checking with your venue.
Beaches and sea
West-coast beaches are still calm and swimmable in April. Toward late month and into May the southwest monsoon builds, and conditions begin to change.
