Delayed by a week, the southwest monsoon has hit coastal and south interior Karnataka and is expected to cover the entire state in two days, the India Meteorological Centre - Bengaluru said on Thursday.

The Bengaluru Met Centre confirmed the onset of monsoon after assessing rainfall on Wednesday and the early hours of Thursday.

"The southwest monsoon has arrived in south interior Karnataka and coastal Karnataka. Some parts of north interior Karnataka received rainfall on Thursday," India Meteorological Centre - Bengaluru Director M. Sundar Metri said.

According to IMD sources, the southwest monsoon arrived in Kerala on May 30 and it was supposed to hit Karnataka on June 5 but got delayed due to the low pressure off the Arabian Sea.

Most parts of southern and coastal Karnataka experienced heavy rain. Coastal Karnataka received 27 mm rainfall on Thursday while north interior Karnataka received 26 mm rainfall. South interior Karnataka received 13 mm rainfall.

The IMD forecast generally cloudy sky with light rain or drizzle in Bengaluru for Thursday and Friday.

"Till now, the rainfall is normal. We will caution people when the rainfall crosses region-wise rainfall thresholds," Karnataka State Natural Disaster Monitoring Centre Director G.S. Srinivasa Reddy said.