Chandigarh, May 6 -- As rains lashed the city, the day temperatures plummeted by 10 notches to settle at 26.4degC on Monday, making it the third coldest May day in 70 years. The coldest days so far, were recorded on May 1 and 2 last year, when the day temperatures had dropped to 24.3degC and 25.7degC. The India Meteorological Department (IMD) had started maintaining records for Chandigarh in 1953. On Monday, the IMD observatory in Sector 39 recorded 5.4 mm rain while the airport observatory logged 21.4 mm rain. As per Met officials, thunderstorms are expected to continue on Tuesday, with cool weather likely throughout the week. According to IMD director Surender Paul, the temperature drop is due to a combination of a Western Disturbance, cyclonic circulation over Rajasthan, and a trough over North East India, which is feeding moisture from the Bay of Bengal. While the Western Disturbance will weaken from Tuesday, chances of rain will persist in the region due to other systems. "We can expect below normal temperatures to continue through the week. We are unlikely to see the full effects of the May heat till the second half of the month," Paul further added....