Delhi Heat Wave: Touch And Go Situation Likely

Mercury levels continue to oscillate between 39°C and 41°C over and around the national capital. Base station Safdarjung recorded a high of 39.9°C yesterday, about 2°C above normal and a drop of about 1.4°C from the previous day. The temperature is expected to rise during this week and may even spill over to the start of next week as well. There is a fair amount of chance for Delhi to clock a temperature above 40°C between 24th and 28th April.

The mercury may even breach 42°–43°C for a day or two during this period, more so between 25th & 27th April 2025. This is also in accordance with the seasonal progression of temperature around this time of the month of April.

A western disturbance is approaching the northern mountains tomorrow. An associated cyclonic circulation will also form over the central Pakistan region. This feature will gradually shift eastward over the next three days across north and east Rajasthan, Haryana, Delhi, North Madhya Pradesh, and Southwest Uttar Pradesh.  

A typical pre-monsoon pattern will prevail with an east-west trough through these parts, embedded with small-scale bubbles of circulation. Such a pattern is quite conducive to triggering heat-induced convection and sporadic rain and showers, albeit scattered and for brief periods.

The wind pattern over the Delhi region will be quite variable for the next 4-5 days. Oscillation of the trough in the vicinity of Delhi will frequently change the wind stream between easterly and westerly. Mercury is likely to remain 40°C or above on most occasions in the remaining days of April.

The pentad normal temperatures will rise in the last week of April. This month starts with a pentad normal of 34°C in the first week and climbs to 37°-38°C in the last 5 days of the month. To meet heat wave criteria, the surface temperature needs to breach at least 42°C and preferably 43°C. The conditions are shaping up for stifling heat over Delhi/NCR during this weekend.

Mercury is likely to breach 42°C or more for the first time during this year and the pre-monsoon season as well. The month of April is expected to close by logging a short spell of moderate heat wave in the remaining days of the month. There is an outside chance to have a brief spell of fleeting rain and a light shower in the early hours of the 26th of April morning.  

There is a touch-and-go situation for both the heat wave and light rain.  The spell of rain, if any, will not at all suffice to offer any relief from the excruciating heat conditions expected between 25th and 27th April.