New Delhi, June 5 -- After a scorching day that saw the mercury touch 40.5degC, thunderstorms, rain and strong winds cooled large parts of Delhi on Thursday evening, Thunderstorms and gusty winds touching 91kmph caused temperatures to plunge by 9degC to 19degC in parts of Delhi within hours.

The India Meteorological Department (IMD) upgraded a yellow alert issued for the city in the morning to an orange alert around 7pm as thunderstorm activity intensified across the region.

Till 5.30pm, Ayanagar recorded the highest rainfall at 27.6mm, followed by Mayur Vihar at 24.5mm and Ridge at 19mm. Pragati Maidan received 12.8mm of rain, Palam 10.7mm, Pusa 8mm, Lodhi Road 4mm and Najafgarh 1.5mm. Safdarjung, considered representative of Delhi's w...