Even though the India Meteorological Department (IMD) is looking to alter the monsoon onset and withdrawal dates from their existing ones in some parts of the country, it will not impact either the full duration of rains nor the total quantum of showers.
Senior IMD officials said the change also might not impact the actual arrival of monsoon over Kerala which is June 1, but the date of its progress, onset and also withdrawal over Central and Northern parts of the country might get changed following changing patterns.
The rains after entering India on June 1 covers much of Central and Western India between June 5 to 15 and enters north India from July 1. These dates might get pushed back a bit.
Currently, the southwest monsoon after entering the country in June 1 start retreating from September 1 onwards after completing its four-month journey over the Indian peninsula.
It is normally expected to cover all parts of the country by July 15, but since the last few years, it progresses over Central and North India has been delayed even if reaches Kerala coast on time. This is one of the reasons why new onset and withdrawal dates are being expected in some parts of the country.
The tweaking, according to senior IMD officials, is being done to give farmers correct information about the arrival and withdrawal of monsoon so that they can make informed sowing decisions particularly in the Rainfed western, Central and parts of North India.
But some experts said a change in onset and withdrawal dates could have a far reaching impact on farming schedules and also harvest time for farmers.
“So what happens if kharif crop sowing is delayed, it will push back rabi schedules and late rabi sowing particularly in crops like wheat could harm final yields if temperatures go up sharply,” Shiraz Hussain, former agriculture secretary said.
The good news is that the overall quantum of rains will remain at 887-889 millimeters and the monsoon season will be in place for four months. Only the normal onset and withdrawal dates in some parts might be altered because of changing pattern of the showers, M Rajeevan, secretary Ministry of Earth Sciences told Business Standard.
So instead of June to September, the monsoon season could be from July to October or maybe middle of July to middle of September, in some parts of the country.
“Usually, we change the normal rainfall that an area receives after every 10 years and take the latest 50-year average, but after a long time considering new normal onset dates for various regions particularly for Northern and Central parts of the country as the monsoon arrivals in these parts have been getting late since the last few years,” Rajeevan said.
He said a high-powered panel of experts constituted by the IMD had submitted its report on the new onset and withdrawal dates in some parts of the country which is being evaluated and a final call will be taken on the same.
Senior officials said agriculture ministry needs to alter its crop sowing advisories for Central and North India, if the change happens.
“Agriculture Ministry needs to give proper advisories to farmers to inform them about change in sowing schedules, also we need to observe whether it is a long term trend. Already, in Punjab farmers have started planting paddy only after the first showers arrive, but yes to me overall crop production might not get altered as the season will be of four months,” Mahendra Dev, Director of Indira Gandhi Institute of Development Research (IGIDR) told Business Standard.