India’s monsoon has turned wild. Half of the country is reeling under floods after extraordinary downpours, with Punjab facing its worst deluge since 1988. Some parts of Punjab, Haryana and Rajasthan saw rains more than 1,000% above normal in just 24 hours, the Indian Meteorology Department (IMD) says.
Between 28 August and 3 September, rainfall in northwest India was 180% above average, and in the south, it was 73%. The rains have caused landslides and floods in several parts of the country, inundating villages and towns and killing hundreds. But how did the rainfall become so intense?
Changing monsoon
The climate crisis is changing the behaviour of the monsoon. Scientists say one of the main changes is that there is a much higher amount of moisture in the air now, from both the Indian Ocean and the Arabian Sea due to warmer climate.
Also, in the past, monsoon rains were steady and spread evenly over the four months – June, July, August and September. But meteorologists say they have observed that rains now often fall in huge volumes within a small area in a short span of time after a prolonged dry spell.
Experts say this is increasingly happening in the mountainous regions where massive moisture-laden clouds hit the hills, pouring huge amounts of rain very quickly in a small area – a phenomenon that is known as cloudburst.
This was one of the main causes for the havoc in the Himalayan states of Uttarakhand, Indian-administered Kashmir and Himachal Pradesh during the first week of August. But the reasons change as you start travelling down south from the Himalayan states.
Westerly disturbances
In August, prolonged heavy and even extremely heavy rainfall lashed states like Punjab and Haryana for days. Meteorologists say it was mainly because of the interaction between the already existing monsoon system in the Indian subcontinent and westerly disturbances, a low pressure system that originates in the Mediterranean region and travels eastward.
This westerly disturbance often carries a mass of cold air from the upper levels of the atmosphere and when it meets the relatively warmer and moisture-laden air in lower levels – like the current monsoon has – it can lead to intense weather activity.
IMD has also confirmed that the extreme rainfall for a sustained period in northern India and other parts of the country was mainly because of the clash of the monsoon system and the westerly disturbances.
Scientists put that down to jet streams – narrow, fast-flowing currents of air in the upper atmosphere that travel from west to east around the globe. They say that global warming is making these currents increasingly “wavier”, which means it’s meandering and not following a steady path. And that influences other weather systems too.
Studies have shown that wavy jet streams are leading to extreme weather events around the world, including in India recently, where the subtropical jet stream steered the westerly disturbances unusually far south into northern parts.
Unstable Mountains and Man-Made Disasters
Heavy monsoon rains trigger floods across India, but other factors like flash floods and landslides also play a role. Regions downstream of the Himalayas, including parts of India and Pakistan, have seen floods even without significant rainfall.
Scientists point to glacial lake bursts, underground lakes opening through cracks, and landslides creating temporary dams that later collapse. Climate change is accelerating glacier and permafrost melt, destabilizing mountains as snow and ice that once held slopes together disappear. Rainfall is now reaching higher altitudes where it used to snow, further weakening terrain.
Human activities worsen the crisis. Settlements and infrastructure projects—like highways, tunnels, and hydropower plants—disrupt natural water paths and weaken mountain stability. Poor maintenance of embankments and clogged urban drains add to the risk. Experts stress urgent action to reduce damage from floods and extreme weather. (BBC)
