India, Sept. 28 -- The Capital's air quality index (AQI) spiked to a 15-week high on Saturday, before stronger winds swept out some of the pollutants in the evening.

Delhi clocked a 24-hour average AQI of 169 (classified as "moderate") at 4pm on Saturday, according to the Central Pollution Control Board's (CPCB) evening bulletin. This was the highest reading on the city's pollution gauges since June 13 this year, when the meters hit 187.

However, Saturday' AQI improved to 155 by 11pm.

The 24-hour average AQI was 120 (moderate) on Friday as well as Thursday.

CPCB classifies an AQI of 0 to 50 as good, 51 to 100 as satisfactory, 101-200 as moderate, 201-300 as poor, 301-400 as very poor and 401-500 as severe.

Since early June, Delhi has...