The Thai Meteorological Department (TMD) warned the temperatures in Thailand may keep rising until the end of this month, before the rainy season begins.
The TMD has forecast that from April 28 to May 7, temperatures in Thailand will remain high.
From April 28 to May 2, hot weather will prevail due to low chance of rainfall, except for around the Andaman Sea area in the South, it said.
The wind direction will start to change from May 3 to 7, with the appearance of rain clouds in the Northeast and the East. Temperatures will then fall.
The department said Thailand's summer normally runs from mid-February until mid-May.
On Sunday, the highest temperatures in the north ranged from 39 to 44°C, while temperatures in the northeast ranged from 42 to 44°C.
Temperatures in the central plain were measured at 39 to 44°C and the east ranged from 35 to 42°C.
In the southern region, temperatures ranged between 35 and 41°C in the east, while the western side ranged from 35 to 38°C.
Temperatures of around 35 to 42°C were seen in Bangkok and its adjacent provinces.
