Delhi's AQI reached 409 due to an accumulation of local pollution elements, ending the 28-day break from 'severe' air quality. The visibility is expected to be reduced to 200 meters due to fog on Saturday morning. Rain has been forecasted to potentially improve the severe AQI. The ventilation factor and surface wind direction are crucial factors affecting air quality. PM2.5 emissions from transport, industries, and other sources contribute to the pollution. PM2.5 and PM10 levels spiked, exceeding safe limits. The temperature will rise, and there is a possibility of rain or drizzle in NCR.