The AQI in Mumbai improved on Wednesday, with the Air Quality Early Warning System showing a reading of 141, at 5:30 am. This comes a day after the city recorded 'poor' to 'very poor' air quality. Byculla, Chembur, Worli and Sion recorded AQI at 171, 148, 94 and 89 respectively. However, AQI was 242 at Bandra Kurla Complex.