The air quality in Kathmandu Valley has been worsening since Sunday due to the rise in forest fires across the country.

According to IQAIR, a Swiss group that collects real-time air-quality data from around the globe, the Valley’s Air Quality Index (AQI) read 265 at 11:06 am on Wednesday with particulate matter pollution (PM2.5) levels 34 times the World Health Organisation’s annual air quality guideline value.

On Sunday, the Valley’s air quality had reached concerning levels with AQI as high as 413. Despite slight improvement, PM2.5 levels remained at unhealthy levels of 250 micrograms per cubic metre on Monday and 223 micrograms per cubic metre on Tuesday.

Very unhealthy air quality means health warnings of emergency conditions with the entire population likely to be affected and many may experience serious health effects.

Also read: Kathmandu Valley’s toxic air exacerbates respiratory illness

With worsening air quality, Kathmandu has topped the global ranks of the most polluted city for the past few years.

In 2021, the government had decided to close schools across the country for four days in the wake of rising air pollution levels.

Kathmandu’s AQI level had remained between ‘very unhealthy’ and ‘hazardous’ levels then, with the highest AQI level recorded at 411 at 9:45 am on March 27, 2021, with PM2.5 at 366 micrograms per cubic metre.

The Kathmandu Valley’s Air Pollution Management Action Plan provides that the authorities can declare a public health emergency whenever AQI readings exceed 300. However, none of the agencies concerned has considered declaring a public health emergency to mitigate the impact of air pollution.

According to the Meteorological Forecasting Division of the Department of Hydrology and Meteorology, the weather will remain partly cloudy in the hilly regions due to the influence of Westerly winds.

The hilly regions of Koshi, Gandaki, Karnali and Sudurpaschim provinces may experience light rainfall, thunder and lightning, said Meteorologist Govinda Jha.

Jha added that there was some chance of smoke and haze, covering the Kathmandu Valley, clearing up, but not completely.

Some hilly and mountainous regions of Koshi, Bagmati, Gandaki and Karnali provinces may experience light snowfall, the MET department said.