National capital has been enduring searing heat for the month of April, so far. Base station Safdarjung has persistently recorded above normal day temperature between 01st- 18thApril. Mercury level is likely to breach the threshold normal (36.3°C) for the remaining days of the month. Base station Safdarjung and airport observatory Palam, both are heading for an exclusive record of measuring higher than normal temperature for the entire duration of April.
Safdarjung has recorded 7 heat wave days so far and more are in the offing. Also, the day maximum has reached 40°C or more on 9 days with the highest of 42.6°C on 11thApril. This is the highest temperature in the last 5 years, with a potential to exceed 43°C during fag end of the month. Some parts of the national capital have recorded 15 heat wave days and breached 43°C repeatedly.
As per the pentad normal, the base observatory has an average of 35°C in the first few days of April and ends with a temperature of 38°C. The mean monthly maximum temperature of April was 35.5°C and 37.4°C in 2020 and 2021 respectively. This year, it has been exceedingly hot with average temperature of 40°C between 01st-18thApril. There is no major let up likely over the next 2 weeks. Thunderstorm activity is expected over Delhi/NCR on 20th and 21stApril.
There is a twist in the weather conditions expected over the next 48 hr. There is likelihood of interlude between the prolonged heat spell and most parts of Delhi may elude monotonous scorching heat on 20th and 21stApril. This spell may slide the day maximum to under 40°C on 21st and 22ndApril. Pending short relief on these 2 days, soaring heat will build up again on the weekend.
Western disturbance is arriving on 20thApril, along with an induced cyclonic circulation over Haryana and Rajasthan region. Extension of trough will run eastward from the system up to West Uttar Pradesh, passing across the capital city. Rain and thunderstorm is likely on 20th and 21stApril, accompanied with gusty winds, possibly kicking up dust and reducing visibility. Lightening with squally winds and fleeting showers are quite likely in the evening and night hours on these 2 days. Weather activity on 21st will have more force and spread as compared to the previous day.