Chennai, June 19 : With heavy rain lashing many parts of Tamil Nadu, a holiday was declared for schools in six districts, including Chennai. As per the weather department this is the first time after 1996 that Tamil Nadu has witnessed such heavy rain in the month of June. Holiday has been declared for schools in Chennai, Chengalpattu, Kancheepuram, Vellore, Ranipet and Thiruvallur districts. Thunderstorms and heavy rain has been lashing these six districts since Sunday night and continued on Monday morning. Meenambakkam weather station reported 14 cm of rainfall till 5.30 a.m. on Monday. Automatic rain gauges (ARGs) in Taramani and Nandanam recorded 12 cm of rain and Chembarambakkam recorded 11 cm of rain on Monday morning. Weathermen predicted rain to continue till Tuesday and the IMD predicted the downpour in 13 districts, including Kancheepuram, Chengalpattu, Cuddalore, Perambalur and Tiruchi till Tuesday. The Regional Meteorological Centre (RMC) issued an Orange alert for Chennai and neighbouring districts predicting heavy to very heavy rain. A cyclonic circulation over Southeast Bay of Bengal is persisting between 3.1 to 5.8 km above mean sea level and this is the cause of heavy rain. Heavy rain has led to waterlogging, and traffic was thrown out of gear in many areas of Chennai. /IANS