Southwest monsoon exits Northeast India with 26% rainfall deficit: IMD
Synopsis
Key Takeaways
The Southwest monsoon completed its withdrawal from all eight northeastern states of India as of Thursday, 15 October 2026, the India Meteorological Department (IMD) confirmed, with the retreat occurring close to its historically normal date. The region recorded a 26 per cent deficit in average rainfall over the four-month monsoon season from June to September 2026, raising concerns for the agricultural sector across the region.
Withdrawal Timeline and Onset
The monsoon's departure from the Northeast came roughly in line with the seasonal norm. In 2025, the Southwest monsoon had withdrawn from the entire northeastern region on 14 October, a senior IMD official said. The 2026 season began slightly delayed, with the monsoon advancing into substantial parts of the Northeast on 7 June — two days later than its normal onset date — before covering the entire region by 10 June. A gradual decrease in both maximum and minimum temperatures is expected from now, with winter conditions anticipated from the last part of November, according to IMD.
State-by-State Rainfall Deficit
The deficit was far from uniform across the eight states. Meghalaya recorded the steepest shortfall at 60 per cent, receiving only 1,077.1 mm of actual rainfall against a predicted normal of 2,695.3 mm — a striking anomaly for a state known for some of the world's highest precipitation. Manipur followed with a 46 per cent deficit, Arunachal Pradesh with 44 per cent, and Assam with 28 per cent.
On the other end, Sikkim and Nagaland recorded 9 per cent and 6 per cent excess rainfall, respectively, placing them within IMD's normal category (between 19 per cent deficient and 19 per cent excess). Mizoram and Tripura recorded 19 per cent and 16 per cent deficient rainfall, respectively — also within the normal band by IMD norms.
National Context: A Historic Low
The Northeast's deficit sits within a broader national underperformance. According to IMD, all-India Southwest monsoon rainfall in 2026 stood at 759.4 mm — just 87 per cent of its Long Period Average (LPA) — making it the fourth lowest since 2001 and the 13th lowest since 1901. Rainfall over East and Northeast India combined reached 1,017.1 mm, the lowest on record since 1901. South Peninsular India recorded 542.0 mm, the fourth lowest since 1901 and the second lowest since 2001. Central India, however, received rainfall within the normal category, offering a partial counterbalance.
Agriculture Under Pressure
Agricultural scientists and IMD officials have flagged that adequate monsoon rainfall — particularly in July — is critical for the Kharif season, when sowing accelerates across the country, including the hilly Northeast. The deficit has compounded existing stress in at least one state: a senior official of the Manipur Agriculture Department said the 46 per cent rainfall shortfall, combined with the state's prolonged ethnic conflict, had severely disrupted farming, particularly given inadequate irrigation infrastructure. The official added, however, that the state government had taken 'adequate arrangements and other supportive measures to facilitate farming activities in both the Imphal Valley and the hill districts during the Kharif cropping season.'
What to Watch
With the monsoon now fully withdrawn, attention turns to the rabi season and how states with significant deficits — particularly Meghalaya, Manipur, and Arunachal Pradesh — manage agricultural output. For Manipur, the dual burden of rainfall deficit and civil unrest could translate into a food security challenge heading into winter. IMD's post-monsoon and northeast monsoon outlooks will be closely tracked by both state governments and farmers across the region.