This summer, India saw 536 days of heatwaves, the most in 14 years, with the northwestern region experiencing its hottest June last month since 1901, according to the India Meteorological Department (IMD).

Moderate rain over parts of Delhi-NCR and adjoining areas is very likely to cause slippery roads, low visibility, traffic disruption, and localised waterlogging in low-lying areas, it said.

The Meteorological (MeT) office issued an 'Orange Alert' on Monday due to a heat wave that will continue for the next 48 hours in isolated places in the low hills of Himachal Pradesh.

During the next five days, no relief is predicted in Punjab, Haryana, Delhi, Rajasthan, Uttar Pradesh, Gujarat, and northwest Madhya Pradesh.

The average temperature of 15.03 degrees Celsius in April was 1.58 degrees Celsius higher than the designated pre-industrial reference period average for the month of 1850-1900. 

Heatwave conditions are declared when maximum temperatures exceed pre-defined thresholds: 40°C in plains, 37°C in coastal areas and 30°C in hilly regions, with a departure from normal temperatures of at least 4.5°C.

Extreme weather conditions could also influence India's parliamentary election, the largest in the world, scheduled for nearly seven weeks starting from April 19th. With nearly one billion eligible voters, election campaigning has already commenced.