Monsoon withdrawal to commence from Sept 19; rain deficit stays at 15%: IMD

The withdrawal of the southwest monsoon is expected to commence from September 19, with the all-India monsoon deficit currently standing at -15%, the India Meteorological Department (IMD) said on Monday, noting that the current monsoon was severely impacted by a strengthening El Nino, leaving several districts in the western, southern and northeastern part of the country in a rainfall deficit, which is unlikely to be bridged back.

The monsoon is expected to retreat in west Rajasthan around September 19, compared with the normal withdrawal date of September 17. Last year, the withdrawal began as early as September 14.

However, IMD officials said several parts of the country should see a flurry of rain activity this week, particularly in the west, northwest and parts of the south peninsular region. It said a low-pressure area exists over southwest Madhya Pradesh, southeast Rajasthan and north Gujarat; a trough across Jharkhand, Gujarat, Chhattisgarh and MP; and an upper-air cyclonic circulation over the Bay of Bengal, near Odisha and West Bengal.

“Conditions are becoming favourable for withdrawal of Southwest Monsoon from some parts of West Rajasthan around September, 19, 2026,” IMD said in a statement on Monday, forecasting fairly widespread rains over Jammu, Kashmir, Ladakh, Gilgit-Baltistan and Muzaffarabad from September 15-17; across Punjab, Haryana and Delhi on 16 and 17; isolated activity across west and east Rajasthan from September 15-17. Isolated scattered rains are also likely across Uttar Pradesh till September 18, it said.

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

Down south, Isolated heavy spells are likely over Tamil Nadu, Puducherry and Karaikal till September; over Kerala and Puducherry’s Mahe town till September 16, over south Karnataka on September 15 and along coastal Andhra Pradesh and Telangana from September 18-20.

In central India, isolated showers are expected over Chhattisgarh, Madhya Pradesh and Vidharbha till September 20. In east India, fairly widespread activity is likely over West Bengal and Sikkim till September 20, over Bihar on September 16-17 and Odisha from September 19-20.

The all-India monsoon deficit touched -40% in June before widespread rains in July brought it down to -13% by the end of July. It was -14% at the end of August and stood at -15% overall, as of September 13.

The deficit is largest in the south peninsula region (-28%), followed by east and northeast India (-25%). It is at -6% in central India and -10% in northwest India. Among the states in a deficit—and unlikely to make a recovery—included key agrarian states like Punjab (-40%), Haryana (-23%), Rajasthan (-25%), Bihar (-35%), Karnataka (-29%), Kerala (-27%), Telangana (-20%), Andhra Pradesh (-43%), Tamil Nadu (-26%), Arunachal Pradesh (-42%) and Meghalaya (-59%), data shows.

In its August 31 forecast for September, IMD said below normal rainfall (<91% of long period average (LPA)) was likely. The forecast came a fortnight after private weather forecaster Skymet Weather issued a revised forecast for the southwest monsoon season on August 17, saying monsoon rainfall was expected to be 85% of the long period average (LPA), with a 70% probability of drought.

In its initial forecast issued in April, Skymet had forecast the monsoon to be 94% of the LPA. In its April forecast, IMD said the monsoon was likely to be 92% below the LPA this year. However, in its June outlook, it revised this forecast downward — from 92% to 90% — and attached a 60% probability to a deficient season.