The city breathed easy on Thursday as the air quality marginally improved over Wednesday, when the air quality index (AQI) was recorded at 320. On Thursday, System of Air Quality Weather Forecasting and Research (SAFAR) recorded an AQI of 272. It has forecast the AQI to improve to 266 on Friday. An AQI between 200 and 300 is considered poor and people with heart or lung diseases, older adults and children should reduce prolonged or heavy exertion. Of the 10 locations monitored by SAFAR, five recorded very poor AQI (between 301 and 400). The most polluted location was Andheri with an AQI of 335. The least polluted was Mazgaon with AQI of 186. The meteorological department had attributed the increased pollution levels to the winter conditions and its fluctuations. "When the winds blow from the land, the dust particles are brought in. Similarly, the high humidity levels increase pollution. These two factors keep changing during the winters, hence the change in pollution levels," said an official. The temperatures in the city remained closer to normal on Thursday. According to IMD, the maximum temperature at Colaba was 32.8 degrees Celsius and 32.6 degrees Celsius at Santacruz. The minimum temperatures at Colaba and Santacruz were 22.2 degrees Celsius and 17.6 degrees Celsius. tnn