New Delhi: Delhi recorded another "heat wave" day on Wednesday, the third this month, with the maximum temperature at the Safdarjung Observatory rising to 42.6 degrees Celsius, six notches above normal, the India Meteorological Department said.
The minimum temperature at the Safdarjung Observatory, which provides representative data for the city, settled at 29.5 degrees Celsius.
Delhi had reeled under a heat wave on July 1 (43.1 degrees Celsius) and July 2 (41.3 degrees Celsius) also.
A severe heat wave scorched areas such as Lodhi Road (42.6 degrees Celsius), Pusa (43.7 degrees Celsius), Mungeshpur (43.6 degrees Celsius), Pitampura (43.3 degrees Celsius) and Najafgarh (44.1 degrees Celsius), where the recorded maximum temperatures were at least seven notches above normal.
Heat wave conditions are expected to prevail at isolated places on Thursday too.
For the plains, a "heat wave" is declared when the maximum temperature is more than 40 degrees Celsius and at least 4.5 notches above normal.
A "severe" heat wave is declared if the departure from the normal temperature is more than 6.5 degrees Celsius, according to the IMD.
The IMD had earlier said the southwest monsoon will reach Delhi around July 10, making it the most-delayed in 15 years.
"The monsoon is likely to advance over the remaining parts of west Uttar Pradesh, some more parts of Punjab, Haryana, Rajasthan and Delhi around July 10," it had said.
The weather system is very likely to increase rainfall activity over northwest and central India from July 10, it had added.
According to Kuldeep Srivastava, the head of the IMD's regional forecasting centre here, the monsoon had reached the national capital on July 7 in 2012 and on July 9 in 2006.
In 2002, Delhi received its first monsoonal showers on July 19. The city had recorded the most-delayed monsoon arrival on July 26 in 1987, Srivastava said.
After arriving late by two days in Kerala, the monsoon had raced across the country, covering eastern, central and northwest India seven to 10 days earlier than normal.
But then, with conditions being unfavourable for its advance, the monsoon weakened and entered a "break" phase.
The meteorological office had earlier predicted that the wind system may reach Delhi by June 15, which would have been 12 days early.
Normally, monsoon reaches Delhi by June 27 and covers the entire country by July 8. Last year, the wind system had reached Delhi on June 25 and covered the country by June 29.