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India’s southwest monsoon may remain weak or stalled for a week, with five rain-suppressing factors active at the same time.
Weather observers point to developing El Niño conditions, weak Madden-Julian Oscillation activity, dry westerly winds, a weak Somali Jet and neutral Indian Ocean Dipole conditions.
The monsoon made a slightly delayed onset over Kerala on June 4 and covered most of southern, eastern and north-eastern India by June 15, but its progress has since slowed.
India recorded a 38% countrywide rainfall deficit between June 1 and June 17, with central India facing the highest deficit at 62%.
Experts say moisture-bearing winds are reaching the country, but weak convection and poor wind convergence are limiting rainfall over the core monsoon zone.
All five major factors that can suppress monsoon rainfall appear to be active at the same time, raising concerns that the southwest monsoon 2026 may remain weak or stalled over parts of India for another week.
The monsoon, which made a slightly delayed onset over Kerala on June 4, gained momentum and covered most of southern, eastern and north-eastern India by June 15. But its progress has since slowed.
Weather observers say the slowdown is linked to the development of El Niño conditions in the equatorial Pacific Ocean, weak Madden-Julian Oscillation activity, dry westerly winds over north-west and central India, a weak Somali Jet, the absence of low-pressure systems over the Bay of Bengal and neutral Indian Ocean Dipole conditions.
The Arabian Sea branch of the monsoon has been largely stalled since June 8, while the Bay of Bengal branch has remained more active. The continued presence of the subtropical westerly jet stream over north-west India has also been reflected in repeated western disturbances over the region.
Independent weather forecaster Navdeep Dahiya wrote on X (formerly Twitter) that satellite imagery on the morning of June 17 showed weak monsoon conditions. “Subdued cloud clover seen across Bay of Bengal and Arabian sea,” he posted.
He said there was “absolutely no chance of a quick recovery before June 23”, adding that June’s rainfall deficiency could widen to 40-45 per cent if conditions did not improve, “signalling super delayed and weak onset for core monsoon zones of the country which are completely dependent on monsoon onsets for sowing of Kharif crop.”
Weather blog Vagaries of Weather identified five reasons for the current monsoon lull. The first is the development of El Niño conditions in the Equatorial Pacific Ocean. The United States National Oceanic and Atmospheric Administration declared the onset of El Niño in its June 11 update. El Niño, the warm phase of the El Niño-Southern Oscillation, is generally associated with weaker monsoon rainfall.
The second factor is weak Madden-Julian Oscillation activity. The MJO is an eastward-moving pulse of clouds, rain and storms that travels around the tropics every 30-60 days. When it is active over the Indian Ocean, it can help strengthen convection over the Arabian Sea and the Bay of Bengal, aiding monsoon rainfall.
“Madden-Julian Oscillation remains weak and away from the Indian Ocean. There is a possible influence from developing strong El Niño conditions,” Vagaries of Weather said.
The third factor is dry air intrusion from the north and north-west. “Strong western disturbances recently moved across North India. Dry continental air from north/north-west India has spread southward,” the weather blog said. This has limited cloud formation and monsoon convection.
The fourth factor is the weak development of the Somali Jet, a low-level wind current that helps drive the southwest monsoon towards India. The monsoon has also lacked support from low-pressure systems in the Bay of Bengal, which often help pull the monsoon inland. Usually the typhoons in the Pacific Ocean also send remnants of low pressure areas which intensify in the Bay of Bengal which has also not occurred in June 2026.
The fifth factor is the neutral Indian Ocean Dipole. A positive IOD, when the western Indian Ocean is warmer than the eastern side, can support monsoon rainfall. The IOD is currently neutral and is expected to remain so, according to the latest India Meteorological Department forecast.
Raghu Murtugudde, emeritus professor at the University of Maryland and visiting professor at the Indian Institute of Technology, Kanpur, said the issue was not simply a lack of moisture. “Winds are blowing and reaching up to a couple of kilometres as expected. They are bringing in the moisture but atmospheric subsidence is inhibiting convection,” he said.
He said the pattern appeared to be linked to conditions over the Bay of Bengal, where cross-equatorial winds were not curving back into the core monsoon zone as expected. “That’s why the eastern end of the trough is bent over like the handle of an umbrella and producing only spotty rain over the east-northeast,” he said.
“This allows the drier air to intrude into the northwest and fire up thundershowers. The core zone is not getting the convergence of the jet from the Arabian Sea and the return flow from the Bay,” he added.
The subdued monsoon has left India with a countrywide rainfall deficit of 38 per cent between June 1 and June 17, according to IMD data. Central India has recorded the highest deficit, with rainfall 62 per cent below normal. The monsoon has reached only parts of this region.
East and north-east India, where the monsoon has covered almost the entire region, has recorded rainfall 44 per cent below normal. The southern peninsula, despite being fully covered by monsoon winds, has a deficit of 19 per cent.
North-west India, where the monsoon has yet to arrive, is the exception. The region has recorded a slight rainfall excess of 3 per cent, mainly because of repeated western disturbances. Five western disturbances affected north-west India between June 1 and June 17. At least one was active on 12 of the first 17 days of the month.
Despite the current weakness, IMD said conditions remained favourable for the monsoon to advance into more parts of Telangana, Odisha, Jharkhand and Bihar, and some parts of Chhattisgarh, over the next four to five days.
The progress of the monsoon will be closely watched because large parts of India’s kharif sowing depend on timely rainfall. A prolonged lull in core monsoon zones could delay sowing decisions and increase pressure on farmers in rainfed areas.