The day temperature in Delhi is likely to touch 46 degrees Celsius by Tuesday, the Indian Meteorological Department (IMD) said, warning that a heatwave would predominate most north Indian states, parts of Maharashtra and Telangana this week.
Relief is only expected after May 28 as a western disturbance is likely to bring light rainfall, scientist Naresh Kumar with IMD's National Weather Forecasting Centre told news agency PTI.
"Heatwave conditions over some parts, with severe heatwave over isolated pockets, are very likely over Punjab, Haryana, Chandigarh, Delhi, Rajasthan, Uttar Pradesh, Madhya Pradesh, Vidarbha and Telnagana over the next five days," IMD's daily bulletin said on Sunday.
The temperature is likely to oscillate between 46-48 degrees Celsius in all the core heatwave states minus Uttar Pradesh.
This is the first "red" warning issued for heatwave this summer, Mr Srivastava said. The IMD issues colour-coded warnings depending on the intensity of any weather system in ascending order - green, yellow, orange and red.
"The warning has been issued to caution people not to step out between 1pm and 5pm, when heat is most intense," IMD's head of Regional Meteorological Centre Kuldeep Srivastava said.
The heatwave warning comes at a time when lakhs of migrant workers are walking back to their home states amid the Coronavirus lockdown and several were seen crossing the Yamuna river in Delhi at night to escape the daytime heat.
Earlier in February, the IMD had warned for the second year in a row that this summer (March-May) would be hotter than normal by an average of above 1 degree Celsius.
In 2019, India witnessed 73 heatwaves across 23 states with mercury rising up to 50 degrees Celsius and killing tens of people, data shared by the National Disaster Management Authority showed.
Isolated pockets over Chhattisgarh, Odisha, Gujarat, central Maharashtra and Vidarbha, coastal Andhra Pradesh, Yanam, Rayalseema and north interior Karnataka are also likely to experience heatwave conditions till middle of this week.