Pre-monsoon showers bring relief to Delhi; monsoon to hit NCR on Saturday, says Skymet president

Pre-monsoon showers hit Delhi on Thursday morning, providing respite from the sweltering heat that the city has had to cope with for several weeks since mid-May.

“Pre-monsoon activity is likely to continue until monsoon arrives in Delhi national capital (NCR) on Saturday,” G.P. Sharma, president-meteorology and climate change, at private weather forecaster Skymet, told Mint in an interview.

The typical monsoon onset date for Delhi is 27 June, which was revised three years ago from 29 June, according to Skymet.

Pre-monsoon showers are expected to arrive before the rainy season begins, typically between March and May. 

Despite its late arrival this year, the pre-monsoon showers and forecast of the monsoon's arrival bring relief to the northwestern region, including Delhi, that faced sweltering heat during mid-May and the first half of the current month, with temperature breaching 50°C in some areas.

Also read | The price of a truant monsoon

Delhi witnessed nearly drought-like conditions ahead of the pre-monsoon months. March, April and May experienced rain deficit of 75%, 54%, and 99%, respectively. The trail of desiccation continues in June as well.

June has recorded only 6.6 mm of rainfall so far, against the monthly normal of 74.1 mm. The scarcity of rain was also the main reason for excessive heat, with Delhi recording 14 heatwave days in May and June, the highest in 14 years.

The usually rainiest pockets along the Western Ghats and Northeast India remain in a state of distress. The remaining days of the month do not promise any major recovery in terms of rainfall in these regions. 

Monsoon-deprived sectors

India has recorded 19% rainfall deficiency since 1 June, the beginning of the June-September monsoon season.

Sectors such as agriculture, coal-based power plants, and steelmakers rely on summer rain, or the southwest monsoon, as this typically delivers nearly 70% of the rainwater India needs for its farms and to refill reservoirs and aquifers.

Timely arrival of the monsoon is crucial especially for the agricultural sector, considering that around 56% of the net cultivated area and 44% of food production depend on monsoon rainfall. 

Also read | Consumer goods makers hopeful a ‘normal monsoon’ will heat up demand

Normal precipitation is essential for robust crop production, maintaining stable food prices, especially for vegetables, and bolstering economic growth.

Agriculture contributes about 14% to India's gross domestic product, underscoring the importance of a good monsoon.

“Monsoon is seen gathering up pace faster and covering the entire country before its schedule, 8 July after it being stuck over the eastern region for about three weeks,” Sharma said.

Lost momentum

According to the India Meteorological Department (IMD), the southwest monsoon normally sets in over Kerala around 1 June. It then advances northwards, usually in surges, and covers the entire country by around 15 July. 

This year, the southwest monsoon hit the Kerala coast on 31 May but lost momentum after reaching Mumbai on 9 June—two days earlier than scheduled. 

“The eastern arm of the stream came across the worst performance of recent times and not budged at all as the Arabian Sea branch was stuck at Navsari on the West Coast for about 10 days, making the eastern arm from the Bay of Bengal worse and monsoon current being stagnant for over 20 days,” Sharma said.

Under normal conditions, the southwest monsoon covers West Bengal, Bihar, Jharkhand, and Chhattisgarh around this time of the month and enters Uttar Pradesh on 20 June. 

On the western side, the monsoon reaches Ahmedabad by about 20 June and covers half of Saurashtra and central Gujarat. By 25 June, the stream swallows the entire Saurashtra, covering Rajkot and Jamnagar and swaths of North Gujarat, leaving only the Kutch region, according to Skymet.

A Kolkata spell

The eastern region is in for a spell of rain as “conditions are becoming favourable for the speedy advance of monsoon over the next three days and monsoon is likely to reach Kolkata, shortly,” Sharma said.

“The monsoon stream has entered Gangetic West Bengal but remains on the outskirts of Kolkata, Howrah, Hooghly, Midnapore and South 24 Pargana. The northern limit has covered Barasat, Goberdanga and Krishnanagar, the extreme eastern edge of the state,” he added.

Kolkata normally receives the first monsoon rains on 10-11 June, coinciding with its arrival in Mumbai. This year, though, the state has recorded a shortfall of nearly 75%.