At least 18 people were killed and 28 injured in hail and thunderstorm that pummelled parts of Uttar Pradesh, officials said. Railway officials said two uprooted trees blocked railway tracks at two places in Lucknow division.
Uttarakhand, Jammu and Kashmir and Himachal Pradesh are likely to witness thunderstorm, while parts of Rajasthan might see a dust storm.
Four incidents of wall collapse were reported in Delhi from Najafgarh, Transit Camp, Nehru Place, Mohan Garden in Uttam Nagar and Raj Nagar in Palam, Delhi Fire Service said.
The boys were taken to a local hospital where they were declared brought dead, he said. In southeast Delhi's Jaitpur, a man died after a cement slab fell on him. Thunderstorm over northern hill-states and its effect in the plains is due to a western disturbance.
Skies turned dark in Delhi on Sunday (May 13) and a sudden dust storm accompanied by lightning struck the city, bringing temperature several notches down.
Airline travel in Delhi was changed, together with around 70 flights being diverted from the city's airport terminal on Sunday evening.
In West Bengal, 12 people were killed and more than 15 injured after lightning and heavy rain on Sunday, with 5 deaths being reported from Howrah district, 2 deaths each in Paschim Midnapore, North 24 Parganas and Nadia districts, and one in Murshidabad district.
Meanwhile, the Met department will add 30 doppler radars in the next two-three years across the country, of which several will be in the northeast, a senior IMD official said.
Five people each were killed in Bareilly and Barabanki districts. The disruption was caused after a tree fell on the tracks of the route between Rajiv Chowk to RK Ashram metro stations.
With this, dust storm, and thunderstorm are expected over Delhi and its adjoining areas of Noida, Gurugram, Ghaziabad, Faridabad during the evening hours of today.
In Andhra Pradesh, nine persons were killed in lightning strikes.
As the storm blew at a high speed of 70 km per hour, mercury crashed from 39 degrees Celsius at 4 p.m.to 25 degrees half hour later in the national capital, the India Meteorological Department (IMD) told IANS.