Monsoon withdrawal begins: India faces 15% rain deficit as season nears end

Delhi: The southwest monsoon has started withdrawing from India, marking the beginning of the end of the June-September rainy season after cumulative rainfall remained nearly 15% below the long-period average. The India Meteorological Department (IMD) has indicated that the season could end with a significant rainfall deficit, while El Niño conditions are expected to strengthen further.

The IMD announced that the southwest monsoon began withdrawing from west Rajasthan on September 19, two days later than its normal withdrawal date of September 17.

The withdrawal line currently passes through Ramgarh, Mohangarh, Phalodi and Khajuwala. Conditions are favourable for the monsoon to retreat from more parts of Rajasthan, Punjab, Saurashtra and Kutch over the next three to four days.

The complete withdrawal of the southwest monsoon from the country normally takes place by October 15.

Rainfall deficit reaches 14.9%

Between June 1 and September 19, India's cumulative rainfall was 14.9% below the long-period average, putting the season in the deficient category according to the IMD's classification.

Rainfall has varied considerably across regions. Central India has received rainfall within the normal range, while northwest India recorded a 9.2% deficit, east and northeast India a 25.7% deficit, and south peninsular India a 28.5% deficit.

Fourteen states, including Bihar, Punjab and Haryana, along with the five peninsular states, have recorded rainfall deficits of more than 20%.

Season could end with major deficit

The current rainfall pattern suggests that the southwest monsoon season could end with a deficit of more than 10% nationally.

The IMD has also indicated that El Niño conditions are likely to strengthen during the remaining period of the southwest monsoon. El Niño, which involves warmer-than-normal sea surface temperatures in parts of the equatorial Pacific, is often associated with weaker monsoon conditions in India.

The season could record its lowest rainfall since 2009 if the current trend continues.

What the rainfall deficit means for farming

Despite the overall deficit, kharif crop sowing has progressed relatively well after rainfall improved in July.

However, agricultural risks remain because rainfall has been unevenly distributed across regions and months. Total kharif acreage is around 1.45% lower than last year and 0.72% below the five-year average.

Paddy, India's largest kharif crop by acreage, has seen a decline of nearly 4% compared with the corresponding period last year.

September rain and Bay of Bengal system

The IMD expects September rainfall to remain below normal, with precipitation forecast at less than 91% of the benchmark.

At the same time, a low-pressure area and subsequent depression over the east-central Bay of Bengal could bring significant rainfall to eastern India and coastal Odisha during the coming week.

The start of monsoon withdrawal does not mean rainfall will immediately stop across India. Rain-bearing systems can continue to produce significant rainfall in parts of the country even as the southwest monsoon retreats.

The bigger concern is the cumulative seasonal deficit and its uneven distribution. While central India has received relatively adequate rainfall, substantial deficits in southern, eastern and northeastern regions could affect local water availability and agricultural conditions.

The agricultural impact will also depend on the timing of rainfall rather than just the seasonal total. Adequate rainfall in July helped kharif sowing recover after a weak June, but lower rainfall in August and September could have implications for crop yields and preparations for the rabi season.

The IMD classifies rainfall between 96% and 104% of the long-period average as normal, 90%-95% as below normal, and below 90% as deficient.