Delhi has received over 200 per cent excess rainfall in the pre-monsoon period — March 1 to May 31 — so far due to back-to-back western disturbances in the last two weeks.
The Safdarjung Observatory, Delhi’s primary weather station, has recorded 221 per cent more precipitation (119 mm against a normal of 37.1 mm) during this period.
Normally, it logs 48 mm of rainfall during the entire pre-monsoon period.
The manual weather station at Palam has recorded 109.9 mm of rainfall against a normal of 33 mm.
The rainfall recorded at Lodhi Road (119.5 mm), Ridge (114.2 mm) and Ayanagar (113.4 mm) is at least 220 per cent above normal.
Delhi has been experiencing cloudy weather and sporadic rainfall for the last 15 days, which is rare during this time of the year. May has historically been the hottest month in Delhi, with a mean maximum temperature of 39.5 degrees Celsius.
Officials attribute this to the back-to-back western disturbances, weather systems that originate in the Mediterranean region and bring unseasonal rainfall to northwest India.
Another western disturbance is likely to affect the region starting May 5. Under its influence, cloudy skies and sporadic rain are predicted in the capital until May 7, an IMD official said.
The maximum temperature is predicted to remain below 35 degrees Celsius until May 8.
On Thursday morning, Delhi saw an unusual episode of dense fog, much to the bemusement of its residents. The minimum temperature dropped to 15.8 degrees Celsius, making it the third coldest morning in May since the IMD started keeping weather records in 1901.
According to IMD data, the Safdarjung Observatory has recorded 45.7 mm of rainfall in May so far. On an average, the capital logs 19.7 mm of rainfall in the whole month.
Delhi recorded more than 20 mm of rainfall in April, the highest in the month since 2017, due to back-to-back western disturbances.
The prolonged wet spell has resulted in below-normal maximum temperatures during the pre-monsoon period.
In fact, the Safdarjung Observatory has not reported any heatwave day in the summer season so far.
The IMD has also predicted below-normal maximum temperatures and fewer heat wave days in northwest India this month.
In 2022, Delhi had recorded its second hottest April since 1951 with a monthly average maximum temperature of 40.2 degrees Celsius.
The city saw nine heatwave days in April last year, including four in the first 10 days, which was the maximum in the month since 2010.