Chennai: As the monsoon gains momentum and heavy rains are set to return to western Tamil Nadu districts, cloudy weather may make days warm and nights warmer in the city. On Wednesday, the city's observatories, Nungambakkam and Meenambakkam, recorded a tepid 33.8°C and 34.1°C, which were 3.2 and 2.9 degrees below normal.

Earlier, before sunrise, the temperatures rose to 29.2°C and 29°C, around 1.8 and 2 degrees above normal. Meteorologists said the same weather pattern might continue for the next four days.N Senthamarai Kannan, Director of the regional weather forecasting centre, said the heavy rainfall forecast over western Tamil Nadu districts like Coimbatore and Nilgiris in the coming days might bring some thunderstorm activity over the city.

"This may bring cloudy weather during the day, keeping maximum temperatures in control and causing a rise in the minimum temperatures. If there is a rise, it may be by one or two degrees," he said.On Thursday, the city and the suburbs may receive light to moderate rainfall over some areas with thunderstorms and lightning. The sky may be partly cloudy. Temperatures may reach a maximum of 36-37°C and a minimum of 28-29°C.

IMD has issued a yellow alert for Nilgiris and the ghat areas of Coimbatore districts on June 27 and 28. There may also be light to moderate rainfall at isolated places over Tamil Nadu, Puducherry, and the Karaikal area until July 1.