Mumbai: Mumbaiites on Monday were caught unawares as the city reeled under a heatwave, with the daytime temperature 4.8C above normal. The India Meteorological Department (IMD) recorded a maximum temperature of 37.9C at Santacruz — representative of Mumbai — and humidity levels touched 55%. The minimum temperature recorded at 5.30 am stood at 25.6C, which was 1.6 degrees above normal.
Monday’s spike in mercury and the heatwave warning were not initially part of IMD’s forecast on Sunday, which predicted “hot and humid” conditions. The warning was issued only on Monday noon. A heatwave is declared in coastal areas when the maximum temperature is at least five degrees above normal.
IMD has also forecast a heat wave for Tuesday, with the maximum temperature hovering between 36C and 38C. The sudden spike in temperature has impacted power consumption. The peak power demand in Mumbai shot up to almost 3,900 MW, the highest so far this summer.
“The heat wave is attributed to easterly winds over many parts of the state, including Konkan,” said Sushma Nair, a scientist at the IMD’s Mumbai office. Lower-level easterly winds that are warm and dry delayed the setting of the sea breeze, resulting in higher-than-normal temperatures. Therefore, the humidity levels also dropped. The heatwave will persist tomorrow as well. On Wednesday, temperatures are likely to drop.”
Given the IMD has only two weather stations in the city, some locations in the Mumbai metropolitan region have recorded temperatures of more than 37.9C, even crossing 40C, added Nair. For instance, Rabale in Thane recorded 41C.
On reasons why the heatwave was not predicted on Sunday, a senior IMD official said that temperatures started to rise on Monday since the sea breeze had not set in at its usual time of around 11 am. That’s when IMD decided to declare a heatwave.
With Mumbai’s power generation capacity being around 1,700 MW, the additional requirement is being purchased from the open market, where the per-unit cost varies from ₹5-8 per unit depending on the time of day. Sources said the Maharashtra State Electricity Distribution Company Limited purchased 10,000 MW of power from the exchange at prevailing market rates. “Our peak demand was close to 900 MW, which was around afternoon. This is due to the offices that have high-guzzling air conditioners,” said a BEST official.
Meanwhile, the Indian Railways is making arrangements for improved water supply at its stations in Mumbai. Central Railway (CR) is providing 1,200 water taps, 245 water coolers and 10 tube wells in the Mumbai region, covering CSMT-Karjat/Kasara/Panvel. Likewise, Western Railway (WR) has provided 194 operational water coolers across its stations from Churchgate to Dahanu.
The Ministry of Railways has asked WR and CR to ensure all existing water coolers are functional and meet passenger demand, deploy water tankers when necessary, and conduct regular checks at stations to confirm water availability across platforms. In areas facing water scarcity, CR and WR will collaborate with municipal corporations and state governments for alternative water supply solutions. Continuous assessment of passenger amenities such as water taps, water coolers, fans, and AC waiting halls will also be taken up.