Air pollution in Chiang Mai is improving following summer storms with levels of ultra-fine particulate matter (PM) 2.5 dropping after months of hazardous haze pollution.
Chiang Mai on Sunday saw thunderstorms causing harsh winds and hailstorms, especially in Mon Cham and Mae Rim districts, with the spate of storms helping to clear the dust pollution.
According to the air-quality monitoring website IQAir, Chiang Mai's PM2.5 levels on Sunday morning ranged between 39-59 microgrammes per cubic metre (µg/m3) while the safe level set by the government is 50 µg/m3.
Chiang Mai's wildfire and haze prevention and resolution centre said it detected six hotspots on Sunday. Three of them occurred in national forest reserves, one in a forest conservation area in Omkoi district and the other two in Mae Cham district.
The total number of hotspots found in Chiang Mai since Jan 1 is 12,182.
The Thai Meteorological Department predicts that after tomorrow the wind speed will alleviate dust pollution further in the northern region. Moreover, all 17 northern provinces might see rainfall.
"Summer storms will arrive this week while the rainy season arrives next month," said the department.
It said southern and southeastern winds from the Gulf of Thailand and the South China Sea will cover the upper region of Thailand, causing temperatures to rise.
The Northeast and East are expected to face summer storms, gusty winds and hail as well as lightning in some areas until April 29, with the department adding that the thunderstorms will scatter to other regions afterwards.