Monsoon withdrawal likely from September 19 as India faces 15% rainfall deficit

The southwest monsoon is likely to start withdrawing from parts of west Rajasthan around September 19, the India Meteorological Department (IMD) said on Monday, signalling the beginning of the seasonal retreat even as several parts of the country remain significantly rain-deficient.

The likely withdrawal date is two days later than the normal September 17 schedule. Last year, the monsoon began retreating much earlier, on September 14.

The country’s cumulative rainfall deficit stood at 15% as of September 13, with the shortfall particularly severe over the south peninsula and east and northeast India. Several major agricultural states are unlikely to make up their deficits before the season ends.

Rainfall still expected across several regions

Despite the approaching withdrawal, rain activity is expected to remain active across several parts of India this week.

The IMD said conditions are becoming favourable for the withdrawal of the southwest monsoon from some parts of west Rajasthan around September 19, 2026. A low-pressure area is currently positioned over southwest Madhya Pradesh, southeast Rajasthan and north Gujarat. A trough extends across Jharkhand, Gujarat, Chhattisgarh and Madhya Pradesh, while an upper-air cyclonic circulation is present over the Bay of Bengal near Odisha and West Bengal.

These systems are expected to bring further rainfall before the monsoon begins its retreat.

The IMD has forecast fairly widespread rain over Jammu, Kashmir, Ladakh, Gilgit-Baltistan and Muzaffarabad from September 15 to 17. Punjab, Haryana and Delhi are expected to receive fairly widespread rainfall on September 16 and 17, while west and east Rajasthan could see isolated rain between September 15 and 17.

Uttar Pradesh is also likely to experience isolated to scattered rainfall until September 18.

Mahesh Palawat, vice-president at Skymet, said conditions appeared favourable for the withdrawal to begin towards the end of the week. “We expect it to happen by September 20. Some decent rain is likely in the region before that,” he said.

Southern and eastern states to see more rain

Several parts of southern India are also expected to receive rain despite the approaching retreat.

The IMD has forecast isolated heavy spells over Tamil Nadu, Puducherry and Karaikal through September. Kerala and Mahe are expected to receive such activity until September 16, while south Karnataka could see isolated heavy rainfall on September 15.

Coastal Andhra Pradesh and Telangana are likely to receive isolated heavy rain between September 18 and 20.

In central India, isolated rainfall is expected over Chhattisgarh, Madhya Pradesh and Vidarbha until September 20.

Eastern India is also likely to remain active. Fairly widespread rainfall is forecast over West Bengal and Sikkim until September 20, while Bihar is expected to receive rain on September 16 and 17. Odisha could see fairly widespread rainfall between September 19 and 20.

The IMD's withdrawal process is based on more than a calendar date. It considers a continuous cessation of rainfall for five days, the establishment of an anticyclone in the lower troposphere and a substantial reduction in atmospheric moisture. Further withdrawal is assessed using spatial continuity, falling moisture levels and sustained dry weather.

Several states face deficits unlikely to recover

The overall rainfall deficit has remained elevated despite a substantial improvement after the exceptionally weak start to the season.

The all-India deficit was 40% in June before widespread rainfall in July reduced it to 13% by the end of that month. The shortfall was 14% at the end of August and had widened to 15% by September 13.

The south peninsula has recorded the largest regional deficit at 28%, followed by east and northeast India at 25%. Central India has a 6% deficit, while northwest India is 10% below normal.

Among the states with deficits considered unlikely to recover are several important agricultural regions. Punjab has a 40% shortfall, Haryana 23%, Rajasthan 25%, Bihar 35%, Karnataka 29%, Kerala 27%, Telangana 20%, Andhra Pradesh 43% and Tamil Nadu 26%.

The northeastern states of Arunachal Pradesh and Meghalaya are also facing severe deficits of 42% and 59%, respectively.

Recent reporting has highlighted the agricultural risks associated with the uneven season, particularly for crops dependent on late-season rainfall and adequate soil moisture. Nearly half of India's districts have been reported to be experiencing below-average rainfall, adding to concerns over crop yields and water availability.

Forecasts had pointed to a deficient season

The IMD had already warned of a weak end to the monsoon. In its August 31 outlook for September, the weather agency forecast below-normal rainfall, defined as less than 91% of the long-period average (LPA).

Private forecaster Skymet Weather had also revised its seasonal assessment on August 17, forecasting rainfall at 85% of the LPA and assigning a 70% probability to a drought.

That was a significant downgrade from Skymet's initial April forecast, which had projected rainfall at 94% of the LPA.

The IMD's April forecast had put the expected seasonal rainfall at 92% of the LPA. However, the weather agency revised its estimate to 90% in its June outlook and assigned a 60% probability to a deficient monsoon.

The season's uneven performance has been marked by a sharp deficit at the beginning, a recovery in July and renewed weakness towards the latter part of the monsoon. Current forecasts indicate that rainfall activity will continue in several regions before the seasonal withdrawal gets under way.