Many parts of Delhi recorded a heatwave for the sixth consecutive day on Wednesday, even as the India Meteorological Department said some respite is expected in two days.
The Safdarjung Observatory, Delhi's base station, recorded a maximum temperature of 44 degrees Celsius, four notches above normal. Four out of the 11 weather stations in Delhi recorded a heatwave on Tuesday.
The maximum temperature settled at 46.6 degrees Celsius at the Sports Complex, making it the hottest place in the city. Najafgarh, Mungeshpur, Pitampura and Ridge stations recorded a high of 46.3 degrees Celsius, 46.2 degrees Celsius, 45.7 degrees Celsius and 45.2 degrees Celsius, respectively.
The weather office has issued a yellow alert, warning of heatwave conditions at isolated places in the capital on Thursday. It said the heatwave conditions could lead to "moderate" health concerns for vulnerable people -- infants, the elderly and those suffering from chronic diseases.
Hence, such people should avoid heat exposure, wear lightweight, light-coloured, loose cotton clothes and cover the head with a piece of cloth, a hat or an umbrella, it said.
There is an "increased likelihood of heat-illness symptoms in people who are either exposed to the sun for a prolonged period or doing heavy work," an IMD advisory read.
Weather experts have attributed the heatwave spell to the lack of strong western disturbances and incessant hot and dry westerly winds. They said a fresh western disturbance may induce a cyclonic circulation over Punjab and Haryana which would lead to intermittent pre-monsoon activity in Haryana, Punjab, north Rajasthan and western Uttar Pradesh from June 10-11.
The maximum temperature in the capital may drop to 41 degrees Celsius by Saturday. With the monsoon expected to cover eastern India by June 15, easterly winds will bring in moisture and intensify the pre-monsoon activity in northwest India.
Mahesh Palawat, vice-president (climate change and meteorology), Skymet Weather, said the monsoon is likely to arrive in Delhi around the normal date -- June 27. There is no system in sight which could stall its progress.
A clear picture will emerge in a week or so, he said. Last year, the IMD had forecast that the monsoon would arrive in Delhi nearly two weeks before its usual date. However, it reached the capital only on July 13, making it the most delayed in 19 years.
The monsoon had entered a "break" phase and there was virtually no progress from June 20 to July 8, Palawat recalled. 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.
Based on the absolute recorded temperatures, a heatwave is declared when an area logs a maximum temperature of 45 degrees Celsius. A severe heatwave is declared if the maximum temperature goes beyond 47 degrees Celsius.
(With PTI inputs)