Mumbai is likely to remain hot and humid on Saturday after the Santacruz observatory recorded 37.8°C on Friday, prompting the India Meteorological Department (IMD) to retain its yellow heatwave alert for Mumbai and Thane and issue a warning for hot and humid conditions at isolated places.
Friday’s maximum at Santacruz, the benchmark weather station for Mumbai, was 4.7°C above normal and slightly higher than Thursday’s 37.6°C. The city has recorded three of the 10 highest October temperatures at the station in the past seven days: 37.4°C on October 3, 37.6°C on October 8 and 37.8°C on October 9.
The Colaba observatory recorded a maximum of 37°C, which was 4.4°C above normal and among its highest October readings since 2014. Relative humidity reached 81% at Colaba and 73% at Santacruz, increasing the discomfort associated with the high temperatures.
The IMD attributed the spike to an anticyclone over Mumbai and neighbouring areas. The circulation pattern has stalled the sea breeze that normally brings relief to the city’s coastal areas. IMD scientist Sushma Nair said the system was well organised and that clear, cloudless skies had further contributed to the rise in temperatures.
“An anticyclone is a circulation pattern that causes air to sink towards the ground. The system over Mumbai is well organised, and clear, cloudless skies have further contributed to the rise in temperatures,” Nair said, according to the IMD explanation reported by the Times of India. She said the system was expected to become less organised and shift slightly on Saturday, which could bring some relief.
The weather pattern has affected the wider Konkan region, where several locations recorded temperatures between 38°C and 39°C. Weather experts cited prevailing northeasterly and easterly winds over Maharashtra as another factor delaying the development of the sea breeze and allowing temperatures to rise along the coast.
Mumbai’s recent heat has followed an earlier-than-usual withdrawal of the monsoon. The monsoon withdrew from the city on October 3, compared with the normal withdrawal date of October 8. September was also largely dry, with limited thunderstorm activity, including the type of storms often seen during the withdrawal phase.
For coastal areas such as Mumbai, the IMD’s heatwave criteria consider both the absolute maximum temperature and its departure from normal. A heatwave is declared when the maximum temperature reaches at least 37°C and remains 4.5°C or more above normal for two consecutive days.
Santacruz’s highest October temperature since 2014 was 38.6°C, recorded on October 17, 2015. Colaba’s highest during the same period was 37.2°C, recorded on October 30, 2018. The IMD’s yellow alert for Saturday will remain the immediate weather advisory for Mumbai and Thane as officials monitor the weakening and movement of the anticyclone.
