The maximum temperature in the capital city between 8:30 am on Wednesday and 8:30 am on Thursday was recorded at 23.8 degrees Celsius, the lowest for May since 1951.
The minimum temperature was at 19.3 degrees Celsius, which is seven notches below normal.
Numbers showed that the temperatures in Delhi during the period were lower than Srinagar and Dharamshala, places with much cooler climes compared to the capital city.
During the 24-hour period, Delhi also saw a record 119.3 mm rainfall, almost double the previous May record (60 mm, May 24, 1976).
The heavy rains resulted from the interaction between Tauktae and a western disturbance, the IMD said in a release.
Rain is likely to decrease as the day progresses, news agency PTI quoted Met department as saying.
As per IMD’s rainfall classification system, below 15 mm is light, 15-64.5 mm is moderate, 64.5 mm-115.5 mm is heavy and 115.6 mm-204.4mm is very heavy. “Extreme heavy” refers to rainfall above 204.4 mm.