Cool mornings persist as AQI worsens

Mumbai faces deteriorating air quality with an AQI of 136 despite cool temperatures, prompting civic action against construction violations.

Mumbai: Even as cool mornings persist, on Monday the city awoke once again to a hazy morning, with air quality deteriorating across the city and residents complaining of a worsening Air Quality Index (AQI).

Mumbai, India – 29, Dec 2025: Heavy smog covers the high rise building, at South Mumbai in Mumbai, India, on Monday, Dec 29, 2025. (Photo by Bhushan Koyande/HT Photo)

Chart.

According to the India Meteorological Department (IMD), Santacruz recorded a minimum temperature of 17°C, which is normal for this time of year, while the maximum stood at 32.1°C, 0.5°C above normal. At Colaba, the maximum temperature was 31.5°C, 0.5°C above normal, while the minimum settled at 20.3°C, 0.4°C above normal.

An IMD official said, “The city is likely to see minimum temperatures between 16°C and 18°C over the next few days, while the maximum (temperature) will remain between 31°C and 32°C, with stable conditions expected to persist.”

Despite the comfortable temperatures, air quality worsened across Mumbai. The city’s overall Air Quality Index (AQI) stood at 136, placing it at the moderate category. PM2.5, fine inhalable air pollutants with diameters of 2.5 micrometers or less, and ozone (O₃), a major component of smog, were identified as the dominant pollutants at 26 of the 30 monitoring stations, according to data from the Central Pollution Control Board (CPCB).

Several locations also reported elevated AQI levels. In the Bandra Kurla Complex (BKC), the IITM station recorded an AQI of 154, while the MPCB station reported 123, though the latter saw PM2.5 peaks reaching 299, indicating sharp pollution spikes during the day. Byculla recorded an AQI of 146, with PM2.5 peaking at 206, while Chakala–Andheri East (IITM) reported a high AQI of 180.

In the eastern suburbs, Chembur (MPCB) recorded an AQI of 161, with PM2.5 levels peaking at 245, placing it among the worst-affected areas. Other locations with elevated readings included Ghatkopar (152), Powai (164), Sion (142), Siddharth Nagar–Worli (139) and Navy Nagar–Colaba (141). Borivali East reported AQI readings of 112–119, while Malad West (142) and Mazgaon (126) also remained in the moderate range.

A senior BMC official acknowledged sensor-related issues at a few locations. “There was a problem with the ozone sensor at Sewri, and a similar issue is occurring in Kandivali. Penalties have been ordered against the concerned person in charge of those monitors. We are also continuing our action against air quality norm violators in the city. Otherwise the conditions have remained stable,” the official said.

An inspection by the BMC’s air pollution mitigation squad at an under-construction building near the Bandra high court found violations of dust-control and air pollution mitigation norms, triggering civic action. Following the inspection, a show-cause notice was issued on December 26, warning of a possible stop-work order if the lapses continue. The action comes amid heightened scrutiny of construction sites as Mumbai’s air quality remains under pressure.

A BMC official said, “once they comply with the conditions, we will revoke any action.”

A similar case was reported from BKC, where a stop-work notice was issued on December 17 at the bullet train site for violations, halting work. “We are waiting for them to comply and install dust suppressors. They have been given ample time, after they comply the stop-work orders will be revoked,” an official said.