Meteorologists have said that the thick blanket of haze covering Kathmandu Valley will clear only after rainfall.

The weather condition, attributed to active forest fires in Nepal and other combustion sources including biomass or fuel urning, has been a big concern of late.

Meteorologists say the western regions of the country may receive some rain with thunderstorms but there are no indications that Kathmandu will get showers anytime soon.

According to Barunraj Poudel, a meteorologist at the Meteorological Forecasting Division in Tribhuvan International Airport, the haze will clear only after rainfall or movement of air. “There has been no air movement over the Kathmandu skies. It has also not received any rainfall,” he said.

For the past one week, Kathmandu and several other parts of the country have been shrouded in a blanket of haze, with increased concentration of particulate matter, which experts say, is enough to penetrate deep into the lungs.

The haze has also affected flights, said meteorologists. Normally a flight requires the visibility of 3,000 metres. However, the haze has limited it to 1,500 to 2,000 metres, said Poudel.