Many places in the city witnessed rains accompanied by thunder and lightning as storm cells moved in from the sea on Thursday evening.
The Regional Meteorological Centre (RMC), Chennai, upgraded its warning to yellow alert till 8.30 a.m. on Friday as it forecast heavy rain at isolated places over Chennai, Chengalpattu, Kancheepuram and Tiruvallur districts.
From 8.30 a.m. till 10 p.m. on Thursday, the automatic weather station at Nungambakkam recorded 55 mm of rainfall. The station at Villivakkam recorded 35 mm, ACS college in Kancheepuram recorded 23.5 mm, Chembarambakkam 21.5 mm and Sathyabhama University 38 mm.
Meanwhile, the Chennai Collector announced holiday for schools and colleges in Chennai district on Friday because of heavy rain.