The city woke up to hazy conditions for the third day in a row. While the weather bureau said there was a marginal improvement in foggy conditions, pollution levels further increased from Saturday.

The pollutant-measuring indicator — air quality index (AQI) — was recorded at 240 (poor) on Sunday as compared to 237 (poor) on Saturday.

The System of Air Quality Weather Forecasting and Research (SAFAR) predicted an AQI of 224 (poor) for Monday.

AQI of PM2.5 pollutant — small pollutant particles that can easily enter the lungs and cause respiratory ailments — between 0-50 is good, 51-100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301-400 is very poor, and 400 above is severe.

The India Meteorological Department (IMD) said visibility in the city improved as fog reduced.

Visibility levels were between 4,000 and 10,000 metres. Mumbai’s average visibility levels are between 10,000 and 20,000 metres. On Saturday visibility levels were between 1,000 and 4,000 metres, said IMD officials.

Officials from the weather bureau said calm winds were expected over the next two days. “The fog marginally cleared by Sunday afternoon but the layer of dust, due to the process of inversion, is still suspended close to the surface. This is leading to smog formation, which is expected to continue till Tuesday or until winds pick up speed,” said KS Hosalikar, deputy director general, western region, IMD.

Of the 10 locations in Mumbai, Navi Mumbai was the most polluted with an AQI of 349 (very poor), followed by Borivli at 320 (very poor), Andheri 311 (very poor), Bandra Kurla Complex 309 (very poor), and Mazgaon 303 (very poor).

While Worli recorded the cleanest air in the city at 116 (moderate), remaining locations were either in the poor or moderate categories. He added that moisture levels were high during the day, which was allowing the hazy conditions to continue.

Mumbai recorded 95% humidity on Sunday morning that fell to 84% by the evening. While day temperature was a degree Celsius above normal, the night temperature was almost 2 degrees Celsius above normal.

The weather bureau has issued a forecast for mist or fog likely to occur on Monday morning.