Three persons (two women and a boy) died of electrocution here, Minister for Revenue and Disaster Management, KKSSR Ramachandran said. It was a repeat of scenes witnessed here last month as motorists struggled to manoeuvre their vehicles on flooded roads and subways while showers led to traffic congestion in the city and suburbs.

Greater Chennai Corporation said that over 145 pumps were used to de-clog inundated locations. Metrorail authorities said services were extended by an hour from 11 PM onwards in view of rains so as to help passengers reach their destinations safely.

Starting from noon, most areas in the city and suburbs began receiving rainfall and it was heavy to very heavy in several locations. According to India Meterological Department (IMD), the highest rainfall of 17.65 CM was recorded in MRC Nagar here. It was 14.65 CM and 10 CM at Nungambakkam and Meenambakkam respectively.

In other areas, including those falling under neighbouring Tiruvallur and Kancheepuram districts, the showers ranged from 1 CM (Madhavaram) to 10 CM (Nandanam). The rainfall data was recorded between 8.30 AM and 6.15 PM today.

Isolated heavy to very rainfall activity is likely to continue over north coastal Tamil Nadu and adjoining areas of south coastal Andhra Pradesh during next three days and decrease thereafter, the IMD said. Weather enthusiasts made claims in the social media vis-a-vis the intensity of rains and on showers beating previous records.

One such claim said Thursday's rains in Chennai was the heaviest for a single day in the month of December after 2015. IMD officials here, however, did not confirm such claims. Officials said a conclusion could be arrived at only after looking into actual rainfall for the 24-hour period and following a scrutiny of previous data.

Enthusiast Pradeep John (Tamil Nadu Weatherman) tweeted, "Mylapore crosses 200 mm. One of the craziest spells of lifetime. Chennai City (Nungambakkam) beats 2015 annual rainfall."

In another tweet, he said, "2015 annual rainfall is overtaken by 2021 & is the 3rd wettest year of all time behind 2005 & 1996." He had also given data for Chennai city (Nungambakkam) to support his claim.

Tamil Nadu witnessed heavy rainfall during the north east monsoon (October-December) monsoon and according to the weather office, presence of 'convective cells,' led to rainfall.

A weather forecast by the IMD (issued 12.30 hours on December 30) had said:

"Thunderstorm with moderate rain is likely to occur at a few places over coastal Tamil Nadu. Thunderstorm with moderate rain is likely to occur at many places over Villupuram, Cuddalore and Delta districts, Puducherry and Karaikal. Light rain is also likely to occur at isolated places over Interior Tamil Nadu districts."

With inputs from PTI.