LUCKNOW, Nov. 5 -- The first spell of winter pollution has arrived in Lucknow, with the city's air quality slipping into the 'poor' category on Wednesday, four days ahead of Diwali. The AQI climbed to 223, the highest this season and the first time in 234 days that the city recorded poor air quality.

According to Central Pollution Control Board (CPCB) data, the city's air quality index (AQI) stood at 223 on Wednesday. The private monitoring platform AQI.in recorded a marginally higher reading of 224.

Before November, Lucknow had recorded 'poor' air quality on two days in March, with the AQI at 207 on March 11 and 205 on March 8. In January, the city had six days when the AQI remained in the 'poor' category.

The AQI stood at 120 (modera...