The meteorological office has issued an orange alert warning of a severe heatwave in Delhi on Sunday too.
The blistering heatwave sweeping across Delhi-NCR (National Capital Region) intensified further on Saturday with the maximum temperature in the national capital rising to 42.4 degrees Celsius, the highest in April in five years, and nearing the 45-degree mark in neighbouring Gurgaon.
The capital had recorded a maximum temperature of 43.2 degrees Celsius on April 21, 2017. The all-time highest maximum temperature for the month was 45.6 degrees Celsius on April 29, 1941.
The India Meteorological Department (IMD) said this is the first time in 72 years that Delhi has recorded such a high temperature in the first half of April.
The meteorological office has issued an orange alert warning of a severe heatwave in Delhi on Sunday too.
The IMD uses four colour codes for weather warnings -- green (no action needed), yellow (watch and stay updated), orange (be prepared) and red (take action).
The maximum temperature of 42.4 degrees Celsius at Delhi's base station, Safdarjung Observatory, was eight notches above normal for this time of the year.
At 44.5 degrees Celsius, Gurgaon was 10 degrees warmer than average. Gurgaon's all-time high maximum temperature of 44.8 degrees Celsius was recorded on April 28, 1979.
The mercury settled at 45.2 degrees Celsius in Haryana's Faridabad.
Barring SPS Mayur Vihar, which recorded a high of 40.2 degrees Celsius, all automatic weather stations in the city recorded maximum temperatures above 42 degrees Celsius, IMD data showed.
The weather stations at Ridge, Ayanagar, Mungeshpur, Najafgarh, Pitampura and Sports Complex recorded maximum temperatures of 43.9 degrees Celsius, 43.6 degrees Celsius, 43 degrees Celsius, 43.3 degrees Celsius, 43.4 degrees Celsius and 43.9 degrees Celsius, respectively.
Cloudy conditions may bring some relief from the stifling heat from Tuesday, the IMD said.
Parts of the national capital have been reeling under a heatwave since last week with maximum temperatures hovering above 40 degrees Celsius.
IMD officials said a prolonged dry spell has led to "severe" hot weather conditions in northwest India.
The weather department said northwest India and adjoining parts of central India are predicted to see more intense and frequent heatwave conditions in April.
Mahesh Palawat, vice-president (Meteorology And Climate Change), Skymet Weather, said it is an aberration that the maximum temperature has breached the 45-degree mark in parts of northwest India in the first 10 days of April.
There has been nil pre-monsoon activity, including dust storms and thundershowers, in the region so far. Long-range models have also not predicted any significant weather system in the next 15 days, he said.
There is a good chance that Delhi may record a higher-than-usual number of heatwave days in April, Mr Palawat said.
The capital has already recorded three heatwave days this month and the ongoing heatwave spell is likely to persist for another two to three days, he said.
For the plains, a 'heatwave' is declared when the maximum temperature is over 40 degrees Celsius and at least 4.5 notches above normal. A 'severe heatwave' is declared if the departure from normal temperature is more than 6.4 notches, according to the IMD.
This year, India recorded its warmest March in 122 years with a severe heatwave scorching large swathes of the country during the month.
The weather department attributed the heat to the lack of rainfall due to the absence of active western disturbances over north India and any major system over south India.
The country as a whole recorded 8.9 mm of rainfall, which was 71 per cent less than its long period average rainfall of 30.4 mm. It was also the third-lowest precipitation in March since 1901 after 7.2 mm in 1909 and 8.7 mm in 1908.
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