The Gistda said in its website on Monday that 203 hotspots were detected by the Suomi satellite’s Visible Infrared Imaging Radiometer Suite (VIIRS) on Sunday, compared to 423 on Saturday.
In comparison, neighbouring countries had many more hotspots, the agency said.
VIIRS detected 3,822 in Myanmar, 1,388 in Cambodia, 210 in Laos, 60 in Vietnam and one in Malaysia on Sunday.
Of the 203 hotspots in Thailand, 77 were in national forest reserves, 59 in protected forests, 33 in plantations, 22 on plots granted to farmers, eight in communities and four along highways.
The Gistda said the provinces with the highest number of hotspots are:
• Mae Hong Son: 34
• Chiang Rai: 24
• Nan: 22
The Gistda has warned that provinces that share a border with Myanmar or Cambodia may experience worsening air pollution due to smoke and fine dust particles created by forest fires.