Mercury dips to 16.2°C as several pockets report ozone spikes

According to the India Meteorological Department (IMD), the minimum temperature at Santacruz fell sharply from Tuesday’s 17.4°C to 16.2°C, placing it five degrees below normal, while the maximum was 33.3°C, around 0.7 degrees below normal

Mumbai: The city woke up to its coldest morning of the season on Wednesday with the temperature at Santacruz dipping to 16.2° Celsius. Air quality in several pockets of the city, however, dipped to ‘moderate’ to ‘poor’ and doctors reported a rise in respiratory and viral illnesses linked to pollution.

Mercury dips to 16.2°C as several pockets report ozone spikes

According to the India Meteorological Department (IMD), the minimum temperature at Santacruz fell sharply from Tuesday’s 17.4°C to 16.2°C, placing it five degrees below normal, while the maximum was 33.3°C, around 0.7 degrees below normal.

At Colaba, the minimum stood at 21.6°C, around 1.9 degrees below normal, while the maximum touched 33.5°C, marginally below the seasonal norm.

IMD officials attributed the chill to persistent northerly winds funneling cooler, drier air into the region.

“The below-normal (temperature) trend will ease soon. An easterly wind component is expected to set in from Thursday, which will increase moisture and push up temperatures,” an IMD official told Hindustan Times, requesting not to be identified.

Day temperatures are likely to remain at 33-34°C over the next few days, while night temperatures may gradually rise to 18-20°C, the official said. The IMD has issued a cold wave alert only for Jalgaon and Nashik district, but no such alert has been sounded for the city, he added.

Meanwhile, at 4pm on Wednesday, the city’s overall air quality index (AQI) stood at 156 (moderate), though several monitoring stations recorded much poorer levels, with PM2.5 and ozone being the prominent pollutants.

At Borivali East, Chakala, Malad West, Mazgaon, Shivajinagar, Deonar and Navy Nagar, the early morning PM2.5 concentration crossed 300, pushing AQI into the ‘poor’ category. At some locations, particularly Malad, Mazgaon and Navy Nagar, ozone concentrations also spiked sharply, breaching the 160-200 range in the early morning and afternoon, a pattern that has been observed during stagnant winter conditions.

BMC officials said the civic body has been issuing show-cause notices to construction sites, including large metro and redevelopment projects, where lapses are found.

“We are continuously monitoring ward-level construction activity. Road dust, vehicle emissions and open burning are major contributors to pollution,” a senior BMC official said.

The ozone spikes appeared to be hyper-local episodes influenced by sunlight, vehicle emissions and heat-absorbing concrete surfaces, the official noted.

But air quality expert Sunil Dahiya said ozone was not a primary pollutant, but was created by chemical reactions.

“The solution lies in cutting emissions of precursors, such as nitrogen oxides from combustion and volatile organics from fuels and waste,” he said.

PM2.5 and PM10 were rising due to construction activity, local emissions and slow winds, Dahiya noted.

“Wind speeds have been relatively weak today, and the northerly flow is also transporting pollutants into the city, reducing dispersion, “ he said.

Doctors across the city reported an increase in both pollution-linked respiratory distress and viral infections.

Dr Lancelot Pinto, pulmonologist, said there has been a noticeable worsening in symptoms among patients with asthma, chronic obstructive pulmonary disease (COPD) and lung fibrosis.

“Over the last few weeks, many patients who were stable have landed in the emergency room with wheezing, breathlessness. These irritant-triggered flare-ups are linked to the deteriorating AQI,” he said.

At Bombay Hospital, consultant physician Dr Gautam Bhansali said nearly 70% of recent OPD cases involved sore throat, fever, headaches and cold-like symptoms, which he attributed to a combination of pollution and seasonal viral circulation.

“Cases may increase if the AQI worsens. People must avoid crowded areas, wear masks and stay hydrated,” he said.