Bucking the trend, the much-awaited monsoon rains hit New Delhi a day ahead of the normal onset date, bringing relief for the city which had been experiencing sultry weather for the past few days.

Most parts of Delhi experienced monsoon showers on Thursday morning, which sent the mercury tumbling down by a few notches.

"Monsoon has set in over the capital a day ahead of the normal onset date," India Meteorological Department Director and spokesman B P Yadav said.

But the welcome morning rains led to the usual problem of water-logging on the capital's roads that resulted in traffic chaos at several major intersections during rush hour.

The normal onset date for the capital is June 29.

In the past 106 years, the arrival of monsoon in the capital had been delayed on 63 occasions, while the rain system covered the capital ahead of schedule on 37 occasions.

Monsoon had arrived on the normal onset date of June 29 on six occasions.

Monsoon was delayed the most in the capital in 1987 when the onset happened on July 26, while the earliest arrival was in 1998 when the rains hit Delhi on June 16.

The minimum temperature in the capital at 8:30 a.m. was 28.7 degrees Celsius, which was normal for the season.

However, mercury was sluggish in its movement after rains hit the city at around 11:15 a.m. and had settled at 28 degrees Celsius at 1:30 p.m., the weather office said.