Mumbai has registered 38 degrees only once in the past 11 years – this was in October 2018, when temperatures touched 38 degrees. (Express Photo by Akash Patil)Mumbai has been reeling from hot and humid weather since October began, with daytime temperatures soaring up to 38 degrees. The city’s suburban and island city observatories have registered record-breaking temperatures. There are many factors contributing to Mumbai’s heatwave, and one of them could be found in Madhya Pradesh.The heat spells have led the India Meteorological Department (IMD) to place Mumbai and its neighbouring districts of Thane and Palghar under a heatwave.What makes this October heat in Mumbai record-breaking?On October 11, Mumbai’s Santacruz observatory recorded a maximum temperature of 38 degrees – 4.9 degrees above the normal level, making it the hottest October day since 2015, when the city recorded 38.6 degrees on October 17.However, a day later, Mumbai broke its own record with the suburban station recording 38.2 degrees, and the next day, the suburban observatory recorded 38 degrees.Besides 2015, Mumbai has registered 38 degrees only once in the past 11 years – this was in October 2018, when temperatures touched 38 degrees.What’s fuelled the spike in temperatures?Meteorologists have attributed the current spike in temperatures to a combination of factors, ranging from the local wind directions to the supersized El Niño weather pattern.Amongst the key reasons for the ongoing heat level is an anticyclonic system over southwest Madhya Pradesh and Gujarat, which has led to an influx of clockwise winds. The winds are blowing in from the northwesterly and westward directions, as in Rajasthan.Story continues below this ad“Since the winds are blowing in from the northward direction, they are dry and warm. This has led to an increase in temperatures as well as delayed the influx of sea breeze, which is crucial for cooling down the city. Since there is no cloud cover, the heat feels more direct,” Mahesh Palawat of Skymet Weather Services explained.Mumbai is prone to October heat after the withdrawal of the monsoon, when the sun’s rays are not slanted and are harsher. However, this year, the city experienced one of its earliest monsoon withdrawals on October 3, exposing the city to an early onset of October Heat.For perspective, the normal date of monsoon withdrawal in Mumbai hovers between October 10 and 11.Palawat echoed that a powerful El Niño is also a possible factor for early and warmer October heat this year.Story continues below this adWhen can the city expect relief?The ongoing heat spell is likely to continue until the weekend, following which Mumbai and its neighbouring districts may experience a drop in temperatures.In fact, the IMD has predicted the possibility of cloudy skies along with “one or two spells of rainfall with thunderstorms” from October 17. The post-monsoon showers are likely to be spurred by a change in wind directions, which will usher in moist winds from the south-easterly direction.With light rain on the cards, maximum temperatures in suburban Mumbai could drop up to 35 degrees, while Colaba may experience daytime temperatures up to 34 degrees.While no alerts have been sounded for Mumbai and Thane until now, neighboring districts of Raigad and Ratnagiri have been placed under a yellow alert on Saturday owing to the possibility of thunderstorms and gusty winds.Nayonika Bose is a Senior Correspondent with The Indian Express’ Mumbai bureau. While in the early stages of her career, her focused reporting on local governance and community welfare already demonstrates clear Expertise and Trustworthiness in covering essential civic issues impacting Mumbai's residents. Expertise & Authority (E-E-A-T) Specialized Focus: Nayonika's reporting is dedicated to civic and community issues, providing readers with highly relevant, ground-level information about the functionality and administration of India's largest metropolitan area. Core Coverage Areas: Her articles highlight a strong focus on the fundamental quality of life and public safety in Mumbai, including: Civic Infrastructure: Reports on critical failures and initiatives related to public works, such as the recurring problem of unauthorized building collapses in Navi Mumbai, the construction of new infrastructure projects (like the Dahisar-Bhayandar Link Road and the Mahalaxmi cable-stayed bridge), and the maintenance of essential city services (e.g., manhole cover theft). Urban Governance & Crisis Management: Provides detailed coverage of the Brihanmumbai Municipal Corporation's (BMC) response to major crises, particularly during the monsoon (e.g., heavy rainfall, water cuts, and public health concerns like dengue and malaria) and large-scale public safety incidents (e.g., the hoarding collapse fallout). Community Welfare & Rights: Reports on key social issues, including the financial aid scheme for persons with disabilities, the struggles of Mumbai's hawkers protesting eviction drives, and the dangers faced by workers due to the continuation of manual scavenging in water tanks. Cultural & Heritage Reporting: Covers significant community stories, including the restoration of British-era fountains and the history of institutions like the 126-year-old Chinchpokli cemetery, showing a breadth of interest beyond pure administration. Tweets @nayonikakb ... Read MoreStay updated with the latest - Click here to follow us on Instagram