A summer storms warning has been issued for more than 30 provinces in the northern, northeastern and eastern regions through Wednesday.
The Meteorological Department on Sunday forecasts a possible outbreak of storms and gusty winds in the upper part of the country from Sunday to Wednesday.
Affected provinces include popular tourist destinations such as Chiang Mai, Ayutthaya, Trat, Sukhothai and Kanchanaburi, the weather agency said. Bangkok and its vicinity could be braced by the storm on Wednesday, it added.
The unusual weather conditions are due to a high pressure system colliding with hot air during the summer season, according to the department.
Heavy rain and strong winds on Sunday spoiled a Songkran celebration in Nakhon Phanom, damaging booths, tents and exhibitions displaying traditional Thai New Year culture on a road by the Mekong river in Muang district.