Mumbai faces its first post-monsoon heatwave warning as the India Meteorological Department issued a yellow alert for October 9. The Santacruz observatory recorded 37.6°C on Thursday, which is 4.5°C above normal. Weather observer Abhijit Modak said the current weather pattern was particularly favourable for a sharp rise in daytime temperatures.
MUMBAI: Mumbai has barely had time to bid goodbye to the monsoon and the city is already staring at its first heatwave warning of the post-monsoon season.
The India Meteorological Department (IMD) on Thursday issued a yellow alert for a heatwave in isolated pockets of Mumbai and Raigad for October 9, as temperatures continued to hover several degrees above normal.The warning comes just six days after the IMD announced the withdrawal of the southwest monsoon from Mumbai on October 3, an unusually swift shift from monsoon conditions to heatwave-like weather.On Thursday, the IMD also declared the withdrawal of the southwest monsoon from the entire state of Maharashtra.Mumbai's Santacruz observatory recorded a maximum temperature of 37.6°C on Thursday, 4.5°C above normal, while Colaba recorded 36.5°C, 3.9°C above normal. The Thane-Belapur belt was also hot, recording a maximum of 37.2°C.The jump has been particularly sharp. Just a day earlier, the maximum temperatures at Colaba and Santacruz were 34°C and 35.4°C respectively.For Mumbai and other coastal areas, the IMD's heatwave criteria take into account both the absolute temperature and its departure from normal.A heatwave is declared when the maximum temperature reaches at least 37°C and is 4.5°C or more above normal for two consecutive days.
The 37.6°C recorded at Santacruz on Thursday was also the highest October temperature recorded at the observatory in eight years. The highest October maximum last year was 37°C, recorded on October 17.The October peak temperatures at Santacruz in recent years were 36.5°C in 2025, 37.4°C in 2024, 37.4°C in 2023, 35.4°C in 2022, 36.4°C in 2021, 35°C in 2020 and 36.6°C in 2019.At Colaba too, Thursday's 36.5°C was the highest October maximum since the year 2019. The observatory had recorded 37.2°C in October 2018.Despite the scorching afternoons, minimum temperatures have not shown a similar spike. Santacruz recorded a minimum of 24.7°C on Thursday, close to normal, while Colaba recorded 26.5°C, 1.1°C above normal. Relative humidity remained high at 78% at Santacruz and 89% at Colaba, adding to the discomfort.The city's October record highs, however, remain some distance away. Colaba's highest October maximum is 39.5°C, recorded on October 22, 1968, while Santacruz's October record stands at 38.6°C, recorded on October 17, 2015.Weather experts expect the hot spell to continue through October 14 or possibly into the middle of next week.Independent weather observer Abhijit Modak said the current weather pattern was particularly favourable for a sharp rise in daytime temperatures.Modak said, "The combination of a persistent high-pressure area over Gujarat and easterly to northeasterly winds is currently suppressing the sea breeze over Konkan, allowing temperatures to rise sharply during the day. Mumbai and parts of the MMR could therefore see temperatures approach 39°C in the coming days.""The early withdrawal of the monsoon, below-normal rainfall in September and the lack of a significant post-monsoon thunderstorm spell have further reduced moisture and cloud cover, allowing the land surface to heat up quickly. With these conditions likely to persist, the first half of October could remain unusually hot, with temperatures potentially peaking around October 14," he added.