Delhi on Tuesday recorded the highest temperatures in May in 18 years at 46 degrees Celsius. The last time the national Capital touched 46 degrees in May was in 2002, The Indian Express reported.

The highest ever temperature for the month of May was recorded on May 29,1944 when the city’s temperature soured to 47.2 degree Celsius, according to the the Safdarjung Observatory.

Meanwhile, already-scorching New Delhi got even hotter to become the second hottest city in the country on Tuesday, with a maximum temperature of 47.6 degree Celsius. The weather stations at Palam, Lodhi Road recorded 47.6 degrees Celsius – six degrees above normal – falling in the severe heat wave category. Last year, Palam recorded its hottest day in June at a temperature of 48 degrees Celsius.

The weather office said the temperature in Delhi for the next four days would oscillate between 45 degrees Celsius and 46 degrees Celsius.

The Indian Meteorological Department on Sunday issued a heatwave alert for Rajasthan, Delhi, Uttar Pradesh, Madhya Pradesh, Punjab, Odisha and Telangana over the next five days. The weather agency forecast that maximum temperatures over plains of north India are likely to recede from May 28 onwards and favourable reduction in heat wave conditions is likely from May 29.

Extreme heat can have devastating impacts on the health and livelihoods people. In many places, heat only magnifies urban problems, including a shortage of basic services, like electricity and water. This year’s heat wave also comes at a time when the country is under a lockdown to contain the coronavirus pandemic. Studies predict that under such extreme heatwave conditions, the wet bulb temperatures – a measure of heat and humidity that can indicate the point when the body can no longer cool itself – would be so high that people directly exposed for six hours or more would not survive.

The weather office sounds a heat wave alert when the maximum temperature is at least 40 degrees Celsius and the departure from normal temperature is 4.5 degrees Celsius to 6.4 degrees Celsius.

For the plains, a heatwave is declared when the maximum temperature is 45 degrees Celsius. A temperature of 47 degrees Celsius or above warrants a severe heatwave alert.

In Central India and adjoining interior parts of eastern India, present heatwave conditions are likely to continue for the next two days, IMD said in a statement, Hindustan Times reported. This is because of the dry, north-westerly winds over the plains of northwest India.

Under the influence of a western disturbance and the formation of east-west trough in lower levels, rain and thunderstorms are likely in many parts of northwest India on May 28 and 29 following which, the heatwave will abate, the weather body added.

“Cyclone Amphan sucked out all the moisture from other parts of the country and very dry, northwesterly winds from land side was blowing over northwest India,” Kuldeep Shrivastava, head, regional weather forecasting centre told Hindustan Times. “Plus, we had clear skies and direct sunshine which also led to the peaking of maximum temperatures.”