Twenty-six northern and north-eastern provinces have been found to be suffering excessive PM2.5 airborne pollution today as 258 hotspots were detected, most of them in Chiang Mai.

Forest fires at Ob Luang National Park in Chiang Mai, near Highway 108 from Hot and Mae Sariang districts, spread out of control on Saturday night. Flames were visible on the mountain, sending smoke billowing into the night sky.

According to the Pollution Control Department, PM2.5 levels range from 19.2µg/m³-74.4µg/m³ in the north and 18.9µg/m³-56.4µg/m³ in northeast.

The northern and north-eastern provinces with excessive PM2.5 are Chiang Mai, Chiang Rai, Nan, Mae Hong Son, Phayao, Lamphun, Lampang, Phrae, Uttaradit, Sukhothai, Tak, Kamphaeng Phet, Phetchabun, Uthai Thani, Nong Khai, Loei, Udon Thani, Nong Bua Lamphu, Khon Kaen, Kalasin, Chaiyaphum, Yasothon, Ubon Ratchathani, Nakhon Ratchasima, Buri Ram and Surin.

Air quality in the eastern, southern, western and central regions, including Bangkok, is good, with PM2.5 levels below the 37.5µg/m³ threshold.

The Pollution Control Department predicts that air pollution for the whole country will improve over the next seven days.

Meanwhile, the Geo-Informatics and Space Technology Development Agency (GISTDA) reported that, at 2.16am today, 258 hotspots were detected across the country, including 69 in Chiang Mai, 40 in Lampang, 32 in Tak, 31 in Mae Hong Son and 25 in Lamphun.