Telegraph India. However, in 2025, the average AQI before Diwali was 345, which marginally rose to 351 after the festival. In 2024, the AQI was 328 before Diwali and 360 thereafter. Delhi's AQI has crossed 300 for the first time this season, reaching 307 on Monday. With 36 monitoring stations reporting very poor air quality, experts warn that pollution may worsen ahead of Diwali.