Heavy rains that sank Chennai city in 24 hours was the highest rainfall in the last 10 years, says the Met department. Chennai had 246.5 mm rainfall in the last 24 hours which breaks the record of November 2005 which saw 142.4 mm, said Thambi Narayanan, deputy director general, meteorological department, Chennai. He said the highest rainfall during the north-east monsoon was in November 1976, when the city recorded a rainfall of 452.4 mm. Details