Heatwave conditions are expected over northwest India during the next five days, with Punjab, Haryana, Rajasthan and Delhi predicted to bear the maximum impact, the India Meteorological Department (IMD) said on Thursday.

A fresh heatwave spell will also commence over east and central India from May 18.

The Met office issued an orange alert for Haryana, Punjab, Rajasthan and Delhi, emphasising "high health concern" for vulnerable people, including infants, the elderly, and those with chronic diseases.

It warned of an increased likelihood of heat-related illnesses in people exposed to the sun for prolonged periods or engaging in heavy work.

"Severe heatwave conditions are very likely in some parts of west Rajasthan during May 17-20 and in Punjab, Haryana and Delhi during May 18-20," the IMD said.

The mercury could soar to 45 degrees Celsius in the national capital by Saturday.

A yellow alert has been issued for east Rajasthan, Uttar Pradesh, Madhya Pradesh, Bihar, Gujarat, Jharkhand, Gangetic West Bengal and Odisha.

The Met office had earlier predicted a higher-than-normal number of heatwave days in the northern plains and central India in May.

Normally, the northern plains, central India and adjoining areas of peninsular India experience around three days of heatwaves in May.

April saw record-smashing maximum temperatures in east, northeast and southern peninsular India, prompting health warnings from government agencies and some states to suspend in-person classes in schools.

Several places recorded their highest-ever April day temperatures, with the mercury soaring to 47 degrees Celsius.

At least two people died in Kerala due to suspected heatstroke.

According to IMD data heatwave days in April were the highest in 15 years in Gangetic West Bengal and nine years in Odisha.

Odisha also experienced the longest heatwave spell (16 days) in April since 2016.

On Wednesday, a group of leading climate scientists said similar heatwaves could occur once every 30 years and they have already become about 45 times more likely due to climate change.

The World Weather Attribution (WWA) group emphasised that heatwaves intensified by climate change are making life much tougher for people living in poverty across Asia.

Amid the prevailing but weakening El Nino conditions, the IMD had earlier warned of extreme heat in India during the April-June period, coinciding with the seven-phase Lok Sabha elections which end on June 2.

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