On the Brink of the 2025 Indian Monsoon

On the morning of May 13, 2025, the India Meteorological Department declared that the southwest monsoon had reached the south Bay of Bengal and the south Andaman Sea. Like drumbeats before the curtain goes up, showers lashed parts of Tamil Nadu and Karnataka today. This year’s monsoon is expected to arrive in Kerala on May 27—its earliest in 16 years. The last time it came this soon was in 2009, a year of strange promises and stern withdrawals. That year, it rained early and then stopped. The land went dry. There was drought and panic. The monsoon had teased and disappeared, like a guest who walks in uninvited and then refuses to stay for tea.

Across the subcontinent, this annual arrival is more than just meteorological trivia. It is India’s truest season—one that ignores the Gregorian calendar and obeys a deeper, older clock. The summer monsoon, which stretches from June to September, brings more than three-quarters of the country’s annual rainfall. It irrigates crops, recharges aquifers, fills lakes, regulates electricity, and smooths the rough edges of hope. When it fails, GDP shrinks. When it overstays, lives are swept away. No Indian year is complete without it. No Indian story can afford to forget it.

But what is the monsoon? How does one speak of it without sounding either too technical or too romantic?

Its name comes from mausim, Arabic for “season”—a word that once passed through the lips of spice traders navigating the Indian Ocean, timing their journeys to the shifting winds. In Tamil, the monsoon is simply mazhai, in Kannada male, in Bengali borsha, in Urdu barsaat. But names can’t contain it. It’s not just weather. It’s theatre. It’s history. It is the month of long poems, the rusted spine of the paddy field, the scent of wet red earth rising through an open window. It is, quite literally, the breath of the land.

In Kalidasa’s Meghaduta, a banished lover sends word through a cloud. In Sangam poetry, the monsoon carries messages, grief, and longing. In the Mahabharata, it is the drought before the deluge, the silence before Kurukshetra. Monsoon is not just backdrop—it is plot. Its rhythm is the rhythm of every major Indian epic. It is why farmers still glance at the sky like priests before a shrine, why cinema still sets its most tender songs in the rain.

And yet, for all its cultural weight, the monsoon is also an enigma. It doesn’t follow a fixed script. Some years it arrives late—like 2016, when it reached Kerala on June 8, ten days behind schedule. Other years, like 2013, it comes early, and floods Uttarakhand before anyone can prepare. It has danced in erratic circles across decades, even centuries. In 1918, it arrived as early as May 16 and brought with it such excessive rainfall that famine gave way to flood. In 2002, it missed its mark altogether, marking one of the worst droughts in independent India.

No one—not the weatherman with his charts, nor the old grandmother with her knotted joints—can ever be entirely sure. And this uncertainty is not a flaw; it is the monsoon’s signature.

In recent decades, meteorologists have made impressive strides in deciphering its behaviour. India’s monsoon forecasting, once reliant on analogies and intuition, is now backed by satellites, ocean buoys, computer models, and deep-learning algorithms. Where older forecasts rested on surface pressure and Himalayan snow, today’s models factor in sea surface temperatures, jet streams, wind shear, and even the influence of distant typhoons in the Pacific. It turns out that the monsoon is not merely a local affair. It listens to signals from around the world. A cyclone near the Philippines can tug at it. A warmer Arabian Sea can smother it. The monsoon has pen pals in unexpected places—from the Rossby waves of Central Asia to the typhoon corridors of East Asia. Even high-altitude snow in Tibet and anomalous westerly winds above Japan can tilt its course.

Within India, it takes multiple forms: the classic monsoon depression that spins in from the Bay of Bengal; the mid-tropospheric cyclone that brews quietly above the Arabian Sea; the low-pressure troughs that slither along the western coastline; the offshore vortices that cause torrential rain in Goa or Mangalore while neighbouring districts remain dry. Each of these is a character in the larger drama.

One of the more curious discoveries in recent years is how rain tends to fall asymmetrically. In a typical depression, the southwest quadrant tends to get the heaviest showers—20 centimetres in a day is not unusual. The rainfall is not gentle. It is diagonal, determined, and occasionally devastating. Yet it follows a rhythm. Even the most violent downpours tend to happen in the early morning hours—between 2:30 and 8:30 am—as if nature, like a seasoned writer, prefers to build tension at dawn.

What astonishes scientists, even now, is how much remains unknown. Why does the monsoon sometimes break down in July, only to roar back in August? Why do some depressions move west, while others turn north and vanish? Why is the frequency of monsoon depressions dropping—halved since the early 20th century—even as rain events become more intense and localised?

Climate change has added fresh puzzles. While total rainfall in a season might remain the same, it is now more likely to fall in shorter bursts, over smaller areas. This means more flash floods, more crop damage, more cities drowning in hours. The monsoon, in other words, is not dying. It is becoming wilder, moodier, harder to predict.

Yet prediction is everything. A delayed onset by even five days can affect millions of farmers. A failed forecast can derail the sowing of paddy, pulses, and cotton. Governments watch the monsoon like investors watch interest rates. A good monsoon lifts rural incomes, eases inflation, and boosts the stock market. A bad one triggers price shocks and political anxiety.

This is why scientists obsess over what they call the “march of the isochrones”—a beautiful phrase for the invisible line that marks the monsoon’s northward journey from Kerala to Kashmir. This line doesn’t move uniformly. It surges, pauses, retreats, then surges again. Sometimes it runs up the Western Ghats like a bull. Other times it hesitates over Vidarbha like a shy bride.

Despite advances in modelling and data, the forecasts are still wrapped in caution. The IMD now issues short-range, medium-range, extended-range, and long-range forecasts—each with its own scale of confidence. The bulletins are peppered with words like “likely”, “expected”, “moderate probability”. Behind these words are terabytes of data, running on powerful supercomputers. And yet, at its heart, the monsoon remains a creature of rhythm, not reason.

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