The country is saying goodbye to the summer heat with weather forecasters to announce the start of the rainy season.
Meteorological Department director-general Phuwieng Prakhammintara said the agency will soon officially declare the beginning of the rainy season, with May 26 the tentative date.
People should prepare for changing weather conditions during the transition period between the summer and wet seasons, with strong winds and summer storms likely in some areas of the country, the official added.
The weather agency chief also predicted up to 20% less rain this year compared with last year.
Temperatures in the country hovered between the 20s and early 40s on Sunday with the highest mercury --- 42C -- recorded in Mae Hong Son, according to its website.
The long dry spell has hit several areas, including a reservoir of the Ping River in Doi Tao district of Chiang Mai and Bueng Boraphet, the largest freshwater swamp in the country.
Authorities are scrambling to divert water into the swamp to save fish and other flora and fauna.
Phayorm Duangyu, a fisherman relying on his catch in Bueng Boraphet in Tha Tako district, complained that the sharp drop in the water level is making it difficult for him to launch his fishing boat. The number of fish in the swamp has also dropped due to drought, he added.
Fishermen will be forced to stay home as they cannot take their boats out if the dry spell continues for another two weeks, he added.