Mumbai should have had its monsoon by June 11. A week later, the city was still dry and hot, watching the rain clouds stall offshore. A thousand kilometres east, Bihar was already seeing steady downpours. Same monsoon, same week, two different Indias.
Mumbai’s wait is this year’s headline, but there’s another story underneath: the Indian monsoon is changing its rhythm. Over the decades, its onset has crept later, its retreat later still, and its rain has fallen more unevenly across the country.
The monsoon brings 70–90 per cent of India’s annual rain, according to the India Meteorological Department. It starts the planting clock for nearly half the workforce. So, when its timing and spread shift, the effects reach the fields, reservoirs, and food prices.
This year sharpens the point. The 2026 monsoon is late, lopsided, and projected to be below normal. A developing El Nino is the immediate cause. Five questions show how the season is unfolding, and how the longer pattern is changing.
1. DID MONSOONS COME ON TIME?
Not everywhere. The monsoon reaches India in two arms: one climbs the east, up through Bengal, Bihar, and the northern plains; the other up the west coast, from Kerala to Goa, Mumbai, and Gujarat. This year, the two came apart.
The eastern arm kept its schedule, reaching Bengal and most of Bihar close to their normal dates by mid-June. The western arm stalled, and Mumbai missed its June 11 date by a week and counting.
The map of the season’s first fortnight tells the same story in space. The rain ran short across the west and centre, while pockets of the east and south did better.
2. HAS THE ONSET SHIFTED OVER DECADES?
Yes, and almost everywhere in the same direction: later. Set IMD’s two normal calendars side by side, the old 1901–40 one and the current 1961–2019 one, and the onset arrives later across most of the country. The lag is small in the east and the south, up to four days, and widens inland, reaching 10 to 14 days over the north-west.
But this is a shift between two long-term averages, not a year-on-year march. In the actual record, the date does not trend at all. It just swings.
3. IS THE SEASON CHANGING?
Yes, but at the other end. The monsoon now reaches the country about a week earlier than the old normal. Yet, it begins retreating from north-west India around September 17, instead of September 1 — more than two weeks later. The season has stretched.
A longer monsoon is not necessarily good news. Rain that lingers into the harvest window can damage standing crops as easily as a late start can delay sowing.
4. DOES EVERYONE GET THE SAME RAIN?
No. One region keeps drawing the short straw. East and Northeast India have finished below normal every year since 2022 — even when the rest of the country did well. This year, the map looks set to flip. The IMD’s 2026 forecast puts the Northwest, Central India, and the South peninsula all below normal, with only the Northeast near normal.
5. SO WHAT IS BEHIND THIS YEAR?
The slow drift in the calendar plays out over decades. This year’s sharp, lopsided start has a more immediate cause: El Nino. The equatorial Pacific has warmed into El Nino territory, and the IMD has lowered its 2026 forecast to 90 per cent of normal. El Nino is associated with weaker and more erratic Indian monsoons. It does not guarantee a drought, but it tilts the odds toward one.
El Nino is not acting alone. Forecasters point to a cluster of conditions suppressing the rains at once: dry westerly winds and a weak Somali Jet, which help explain the stalled western arm off Mumbai, alongside a quiet Madden-Julian Oscillation and a neutral Indian Ocean Dipole. The result is the lopsided, below-normal start the charts show.
Put the answers together, and the monsoon looks less like a date on a calendar and more like a moving, uneven season. A late western arm pushes back the sowing of cotton and soybeans across Maharashtra and Gujarat, even as the eastern paddy belt plants on time. When the two halves of the country are planted weeks apart, the strain falls on seed, labour, water and, eventually, prices.
With the all-India outlook already at 90 per cent of normal, every week of delay counts for more.
The calendar says the monsoon arrives on June 1 and leaves by autumn. The real monsoon rarely reads the calendar. In 2026, under El Nino’s shadow, it may be ignoring it at both ends.
– Ends
