Mumbai’s suburbs recorded their hottest October day in eight years on Thursday, with Santacruz reaching 37.6 degrees Celsius as the India Meteorological Department declared a heatwave in Mumbai, Raigad and Ratnagiri for Friday.
The IMD said hot and humid conditions were expected to continue. Thane and Palghar were placed under a yellow warning for hot and humid conditions. In coastal districts such as Mumbai, a heatwave warning is issued when maximum temperatures remain 4.5 to 6.4 degrees Celsius above normal for a sustained period.
Santacruz’s maximum temperature of 37.6 degrees was the highest October reading at the station since October 28, 2018, when the mercury reached 38 degrees. Colaba recorded 36.5 degrees, or 3.9 degrees above normal, according to IMD data.
Temperatures have remained above normal through the first week of October. Colaba recorded 37.4 degrees on October 2, its highest October temperature in 13 years, while Santacruz recorded the same temperature on October 3, its highest October reading since 2019.
The IMD attributed the heat to an anticyclonic circulation that delayed the arrival of the sea breeze, which normally helps cool Mumbai. “The prevalent anticyclonic circulation has delayed the influx of sea breeze, which plays a crucial role in cooling down the region. This has resulted in a spike in the temperatures,” Sushma Nair, a scientist at the IMD, told The Indian Express.
The lack of wind also affected the city’s air quality by allowing pollutants to remain suspended for longer. Mumbai’s overall air quality index rose to 120 on Thursday from 91 on Wednesday, moving from the satisfactory category into the moderate category under Central Pollution Control Board standards.
The CPCB classifies AQI readings from 0 to 50 as good, 51 to 100 as satisfactory, 101 to 200 as moderate, 201 to 300 as poor, 301 to 400 as very poor and readings above 400 as severe. Fourteen of Mumbai’s 20 active monitoring stations recorded AQI levels above 100.
Worli recorded the city’s highest AQI at 163, followed by Deonar at 154, Colaba at 151 and Bandra Kurla Complex at 130. An official attributed the increase to the absence of wind. “There is no wind, which has left the pollutants suspended in the atmosphere for a prolonged period. Until strong winds flow, the pollutants will not be dispersed,” the official said.
The heatwave declaration covers Friday, while Mumbai, Raigad and Ratnagiri remain under the IMD warning and Thane and Palghar under a yellow alert for hot and humid conditions.
