The Northeast monsoon rainfall deficit has become a major concern as the 2026 southwest monsoon season ends with significantly below-normal rainfall across the region. The eight northeastern states recorded about 26% less rainfall than normal during June to September, according to India Meteorological Department data.
Across India, the southwest monsoon ended with a 12.6% rainfall deficit, making 2026 the fourth-lowest monsoon season since 2001. However, the Northeast experienced an even sharper shortfall. Meanwhile, the IMD had not formally declared the monsoon withdrawn from the entire Northeast as of October 3 because the required withdrawal conditions had not been met.
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Northeast Monsoon Rainfall Deficit Remains Significant
The Northeast monsoon rainfall deficit varied considerably among the eight states. Meghalaya recorded the largest shortfall at 60%, followed by Manipur at 46% and Arunachal Pradesh at 44%. Assam also recorded a substantial 28% deficit during the June-to-September season.
Mizoram and Tripura recorded rainfall deficits of 19% and 16%, respectively. In contrast, Sikkim received 9% more rainfall than normal, while Nagaland recorded a 6% surplus. These figures show that the regional rainfall pattern remained highly uneven despite the overall Northeast deficit.
Meghalaya’s rainfall shortfall stands out because of the state’s normally high rainfall totals. The state received about 1,077.1 mm against an expected 2,695.3 mm during the monsoon season. Consequently, the deficit has important implications for agriculture, water availability and local ecosystems.
The regional figures also differ sharply from conditions in other parts of the country. Nationally, India received 759.4 mm of rainfall against a long-period average of 868.6 mm. The 12.6% national deficit therefore masks more severe shortages in several eastern and northeastern areas.
Northeast Monsoon Rainfall Deficit Varies Across States
The Northeast monsoon rainfall deficit affected states differently throughout the four-month season. Arunachal Pradesh, Assam and Meghalaya remained among the most affected areas, with deficient rainfall reported during all four monsoon months.
Arunachal Pradesh recorded a 44% seasonal shortfall. The deficit is significant for a state where rainfall supports agriculture, river systems and numerous local water sources. Moreover, variations in rainfall can affect communities differently because of the state’s mountainous terrain and dispersed settlements.
Manipur also recorded a 46% deficit. The shortage comes against a difficult backdrop for agricultural activity, with farming in parts of the state already affected by prolonged disruption. Lower rainfall can add further pressure to cultivation and water availability where communities depend heavily on seasonal precipitation.
Assam recorded a 28% deficit, while Meghalaya registered the region’s largest shortfall at 60%. Such differences demonstrate why state-level rainfall data remains important. A broad Northeast average cannot fully describe conditions in individual states or districts.
At the same time, Sikkim and Nagaland recorded above-normal rainfall. Sikkim’s 9% surplus and Nagaland’s 6% surplus demonstrate that the region did not experience uniform dryness. Therefore, local weather and water-resource planning must consider individual state conditions rather than treating the Northeast as a single rainfall zone.
Southwest Monsoon Exit From Northeast Remains Gradual
The southwest monsoon began its seasonal transition as September ended, but the IMD had not formally announced its complete withdrawal from the Northeast by early October. The agency requires specific atmospheric conditions before declaring the monsoon’s withdrawal from a region.
According to the IMD explanation reported on October 3, withdrawal requires five consecutive rainless days, the establishment of an anticyclone in the lower troposphere and a reduction in moisture levels. Those conditions had not yet been observed across the Northeast at that stage.
The timing is notable because the monsoon withdrew from the Northeast on October 14 in 2025. Therefore, the 2026 withdrawal process was still being monitored rather than treated as complete in early October.
The monsoon arrived in the Northeast on June 7 this year and covered the entire region by June 10. Its arrival had been closely monitored because meteorologists had expected El Niño conditions to influence India’s seasonal rainfall.
Nevertheless, the end of the main southwest monsoon season does not mean rainfall stops immediately across the Northeast. Weather systems can continue producing rain after the core monsoon period. Consequently, residents and authorities still need to monitor short-term forecasts even as the seasonal pattern changes.
Northeast Monsoon Rainfall Deficit Linked to Wider Weather Pattern
The Northeast monsoon rainfall deficit formed part of a much broader national rainfall shortage during 2026. India finished the June-to-September season with rainfall 12.6% below normal, making it the country’s fourth-lowest southwest monsoon since 2001 and the 13th-lowest since records began in 1901.
The eastern and northeastern parts of India were among the hardest-hit areas. Regional rainfall was around 25% below normal, while South Peninsular India also recorded a deficit of about 24%. In comparison, central India remained much closer to normal levels.
Meteorologists have linked the weak monsoon to strengthening El Niño conditions. The climate pattern generally affects atmospheric circulation in ways that can suppress monsoon rainfall over India. The IMD has also indicated that El Niño could peak around November before gradually weakening.
The national rainfall pattern was also uneven within individual months. June recorded a major shortfall, while July briefly brought improved rainfall. However, rainfall again weakened during August and September, leaving insufficient time for the accumulated deficit to recover before the season ended.
The IMD expects below-normal rainfall to continue across much of India during October. It has also indicated that most parts of the country could experience below-normal rainfall during the October-December period, although some areas of northwest and southern peninsular India may receive normal or above-normal rainfall.
Northeast Monsoon Rainfall Deficit Raises Water and Farming Concerns
The Northeast monsoon rainfall deficit could have implications for agriculture and water resources, particularly in states that experienced the largest shortages. Rainfall supports crop cultivation, replenishes local water sources and influences river and groundwater conditions. Therefore, prolonged deficits can create challenges beyond the end of the monsoon season.
Agricultural impacts may be especially important in Manipur, Arunachal Pradesh, Assam and Meghalaya. Farmers depend on seasonal rainfall to maintain soil moisture and support crop growth. Where irrigation infrastructure remains limited, a prolonged rainfall shortage can increase dependence on available water sources.
Meghalaya’s 60% deficit is particularly significant because the state normally receives substantial rainfall. A sharp decline can affect streams, local catchments and water-dependent activities. However, the actual impact will vary according to local water storage, rainfall distribution and conditions after the monsoon.
In Assam, the 28% deficit also deserves attention because agriculture remains closely connected to seasonal rainfall. A rainfall shortage can influence soil moisture and irrigation requirements even when some districts receive more rain than the state average.
Meanwhile, the 16% deficit in Tripura and 19% deficit in Mizoram point to weaker seasonal rainfall across much of the southern Northeast. Local authorities may need to monitor water availability and agricultural conditions as the region moves into the post-monsoon period.
The situation in Sikkim and Nagaland provides a useful contrast. Both states recorded above-normal seasonal rainfall, showing that regional rainfall deficits do not necessarily translate into identical water conditions everywhere. Consequently, future assessments should focus on state and district-level data rather than relying solely on the regional average.
Conclusion
The Northeast monsoon rainfall deficit has emerged as a major feature of the 2026 southwest monsoon season, with the eight northeastern states recording about 26% less rainfall than normal. Meghalaya, Manipur and Arunachal Pradesh experienced the largest shortfalls, while Sikkim and Nagaland recorded rainfall above normal.
Although the southwest monsoon season ended nationally with a 12.6% deficit, its withdrawal from the Northeast remained incomplete in early October because the IMD’s required atmospheric conditions had not yet been established. The region therefore remains under close weather observation as it moves into the post-monsoon period.
FAQs
What is the Northeast monsoon rainfall deficit in 2026?
The Northeast monsoon rainfall deficit was about 26% during the June-to-September 2026 southwest monsoon season across the eight northeastern states.
Which Northeast state recorded the highest rainfall deficit?
Meghalaya recorded the highest deficit at 60%. Manipur followed with a 46% deficit, while Arunachal Pradesh recorded a 44% shortfall.
Did every Northeast state receive below-normal rainfall?
No. Sikkim recorded 9% above-normal rainfall, while Nagaland recorded a 6% surplus. The other six northeastern states recorded rainfall deficits.
Has the southwest monsoon completely withdrawn from the Northeast?
Not according to the IMD information available in early October. The agency said the conditions required for withdrawal, including five consecutive rainless days, a lower-tropospheric anticyclone and reduced moisture, had not yet been observed across the region.
Why was the 2026 monsoon weaker than normal?
The IMD has linked the weak monsoon to strengthening El Niño conditions. India received 759.4 mm of rainfall during June-September against a normal of 868.6 mm, producing a national deficit of 12.6%.