NEW DELHI: Hit hard by El Niño, this month is set to be India’s driest August ever in records going back to 1901.

The month is likely to log a massive rain deficit of over 33% — with as many as 20 days of the monsoon remaining in a “break” — which has raised the threat of the season (June-September) ending in deficient rainfall.With two days of the month to go, countrywide rainfall in August stood at 160.3mm on Tuesday against a normal of 241mm, 33% below normal.The driest month of August was recorded in 2005, when 191.2mm of rain was logged, 25% below normal.

With the monsoon currently in another break spell, it’s highly unlikely that this month’s total would exceed 170-175mm, which would make it the first time that a rainfall deficit of 30% or more is recorded in August.Weak monsoon conditions continuing for a month, the season’s countrywide rainfall deficit on Tuesday rose to 9%, close to the deficient zone (also known as drought year) of over 10% shortfall in the June-September period.

The monsoon’s performance in September now assumes critical importance and weather models held out hope of increased rainfall after a few days, at least in some parts of India.“We expect a revival from September 2 onwards, when a cyclonic circulation is likely to develop over north Bay of Bengal.

This could intensify into a low-pressure system and bring rain in parts of east, central and south India,” said Mrutyunjay Mohapatra, IMD chief.To put the poor rainfall in August this year in perspective, this will be only the second time in 105 years that the monsoon in July or August will be 30% or more below normal.

The only time during this period when a higher monthly deficit was recorded was in 2002 when July logged a shortfall of 50.6%.

July and August are the two wettest months of the year and the most crucial ones for agriculture.Ironically, the sharp downturn came after an above-par monsoon performance in July, when the country recorded an average of 315.9mm of rain, 13% above normal and the second highest in the last 18 years.

Most experts attribute the failure of rains this month to the El Niño, which had strengthened during the previous month into a “moderate” event and began leaving its signature in the atmospheric currents.“The El Niño kicked in while the Indian Ocean Dipole (IOD) did not turn positive as expected in August.

Another factor that can cause good rain, the Madden-Julian Oscillation (MJO), was not in a favourable phase through the month.

Finally, we had just two cyclones over the South China Sea against a normal of four-five during this period.

Remnants of these cyclones often end up in the Bay of Bengal and enhance rainfall in India,” said Mohapatra.IMD had forecast a below-normal monsoon in August, with the deficit of 6% to 10%, which proved to be quite off the mark.Rainfall in September is likely to be better than in August, experts said, days before the IMD’s official forecast for the month.

“While weather models show that a low-pressure system may form in the first week of September, it’s likely to end in central India instead of travelling across the breadth of the country.

Overall, the monsoon in September is likely to be better but El Niño will continue to play a role.

If the month ends with a modest deficit of 5%-8%, the overall monsoon may not end up in the deficient zone,” said M Rajeevan, former secretary of the Union earth sciences ministry.Rajeevan said the 20 break days in August (counting two in the next two days) are likely to be the highest ever for August.

“The 22 likely break days in July-August are the fifth highest on record,” he added.