Mahesh Palawat of Skymet Weather, a private weather forecasting service, said the monsoon has reached Delhi but the rains will remain subdued.
"We can expect light, patchy rains on Thursday evening and Friday. Dry weather will prevail on June 27 and 28," he said.
Normally, the wind system reaches Delhi on June 27. From this year, the IMD revised the onset date for monsoon. The earlier date for monsoon's arrival in the national capital was June 29.
According to weather experts, the earlier than usual arrival of the monsoon in Delhi can be attributed to a cyclonic circulation over the Bay of Bengal which moved towards southwest Uttar Pradesh on June 19 and June 20, helping monsoon advance further.
A trough line had been persisting for many days over Punjab, south Haryana, south Uttar Pradesh and West Bengal, which sped up the movement of monsoon, they said.
"There are two criteria to declare the arrival of the monsoon in Delhi -- rainfall in the last 24 hours and wind flow pattern,"IMD Director-General Mrutunjay Mohapatra said.
"Monsoon is declared in Delhi after both these factors are fulfilled," he said.
This year, normal monsoon is expected in Delhi.
Kuldeep Srivastava, the head of the regional forecasting centre of the IMD, said the northern limit of the monsoon now passes through Nagor, Alwar, Delhi, Karnal and Ferozepur.
Monsoon clouds had led to rains in some parts of the city on Wednesday but the weather department had said the onset would be declared on Thursday.
Rainfall data from all weather stations for 24 hours till Thursday 8.30 am is required to declare the onset of monsoon, Srivastava had said.