A severe heat wave is declared if the departure from normal exceeds 6.4 notches (File)
A brutal heat wave swept Delhi, with the maximum temperature soaring to 45.2 degrees Celsius on Monday even as the weather office predicted some relief from the scorching heat from June 19.
The national capital was on a 'red' alert, which will remain in force on Tuesday, with the maximum temperature expected to hit 45 degrees Celsius.
Heatwave to severe heatwave conditions were recorded at most places in Delhi with the Safdarjung observatory, the primary weather station of the national capital, registering a high of 45.2 degrees Celsius, 6.4 notches above the season's average.
It was a warm Monday morning as well, with the minimum temperature settling at 33 degrees Celsius, 5.5 notches above normal.
The Palam weather station recorded a maximum temperature of 46 degrees Celsius, seven notches above normal, while the Lodhi Road, Ridge and the Ayanagar observatories registered readings of 45.6 degrees, 46.3 degrees and 46.4 degrees, respectively.
The Najafgarh observatory recorded a high of 46.3 degrees Celsius, seven notches above normal.
The weather office has forecast mainly clear skies with heatwave to severe heatwave conditions at many places in Delhi on Tuesday. It has also predicted strong surface winds during the day.
The threshold for a heat wave is met when the maximum temperature of a weather station reaches at least 40 degrees Celsius in the plains, 37 degrees in the coastal areas, and 30 degrees in the hilly regions, and the departure from normal is at least 4.5 notches.
A severe heat wave is declared if the departure from normal exceeds 6.4 notches.
The India Meteorological Department (IMD) uses four colour codes for weather warnings -- green (no action needed), yellow (watch and stay updated), orange (be prepared) and red (take action).
According to the IMD's seven-day forecast, the national capital will experience slight relief from Wednesday.
The city is expected to be on 'yellow' alert on Wednesday and Thursday while it will be put on 'green' alert on Friday and Saturday.
After Wednesday, a fresh western disturbance will approach northwest India, also affecting the national capital and bringing relief, according to the weather office.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)