Explainer: Bracing for more heatwave days than usual

The India Meteorological Department (IMD) has warned of hotter than usual temperatures this year. From April to June, more heatwave days are expected in the northern, central and eastern parts of the country than what has been the norm. Usually, India records five to seven heatwave days during this period. This year, the number could go up to 12 on an average.

The northeastern region, Jammu and Kashmir and Himachal Pradesh will escape the exceptional heat during this period.

Breaching 40ºC

For the April-June period, a heatwave condition occurs when the maximum temperature in the plains reaches at least 40 degrees Celsius or is 5 degrees above normal. In hilly regions, if the maximum temperature breaches the 30 degrees Celsius mark, the IMD declares a heatwave condition.

Areas affected

States expected to see above-normal heatwave days from April to June include Rajasthan, Gujarat, Haryana, Punjab, Madhya Pradesh, Maharashtra, Uttar Pradesh, Bihar, Jharkhand, West Bengal, Odisha, Chhattisgarh, Telangana, Andhra Pradesh, and the northern parts of Karnataka and Tamil Nadu. This season, states like Uttar Pradesh, Jharkhand, Chhattisgarh and Odisha could see as many as 10 to 11 heatwave days.

Health risks

Elevated temperatures pose significant risks, especially for vulnerable populations like the elderly, children and those with pre-existing health conditions. They are more susceptible to heat-related illnesses such as heat exhaustion and heatstroke. Additionally, prolonged periods of extreme heat can lead to dehydration.

Weather patterns

Global warming is leading to higher temperatures globally, including in India. Regional features such as fewer than normal western disturbances, which bring thunderstorms and rainfall, are also adding to a rise in temperatures. In March this year, India recorded only two instances of western disturbances when it usually records five.

The increase in concrete structures in the last two decades, with the built-up area increasing from 31.4 per cent in 2003 to more than 38 per cent in 2022, is also contributing to a rise in maximum temperatures.

Past instances

2009, 2010, 2016, 2017 and 2024 have been the five hottest years declared by the IMD. In 2024, India recorded its hottest day of the period at 50.5 Celsius on May 28 in western Rajasthan’s Churu. The health ministry attributed 143 deaths to heatwaves between March 1 and June 20, 2024.

Minimising impact

Avoid alcohol, tea, coffee and carbonated soft drinks, which dehydrate the body. High-protein food should also be avoided. Wear lightweight, light-coloured, loose and porous cotton clothes.

ORS and homemade drinks like lassi, torani (rice water), lemon water and buttermilk should be consumed often to keep the body hydrated.

India