More Than Just a Number
When the India Meteorological Department (IMD) calls a monsoon "below-normal," it's referring to the total volume of rain received across the country from June to September compared to the Long Period Average (LPA). A monsoon is considered normal when
rainfall is between 96% and 104% of the LPA. Anything below 90% is classified as a deficient monsoon. However, this single number doesn't tell the whole story. It measures how much rain fell over four months, but reveals little about how it fell—the intensity, distribution, and timing. The lived experience of the monsoon is increasingly being defined by its character, not just its cumulative volume.
The Tale of Two Rains
The crucial difference lies in the nature of the rainfall. A healthy monsoon traditionally involves many days of steady, moderate rainfall. This allows water to gently seep into the ground, replenishing soil moisture and recharging the aquifers that are critical for drinking water and agriculture. What India is increasingly experiencing, however, is a pattern of long dry spells punctuated by short, extremely heavy downpours. These intense bursts can dump a massive amount of water in just a few hours, skewing the overall rainfall statistics. A region might receive its entire monthly quota of rain in a single afternoon, creating a statistical 'normal' that feels anything but.
When Good Rain Goes Bad
For the ground, the difference is night and day. When rain falls too fast, the soil can't absorb it. Instead of soaking in, the water becomes surface runoff, scouring away fertile topsoil and failing to replenish the groundwater reserves we depend on. This is a double-edged sword: the very event that causes flash floods also contributes to long-term water scarcity. Experts note that it's the weak and moderate rain events that are most effective for groundwater recharge. As these become less frequent, our underground water banks are not being refilled, even as deluges wreak havoc above.
A Crisis for Farmers
This new pattern is particularly devastating for Indian agriculture. Crops don't just need water; they need it at the right time and in the right amount. Steady moisture is essential for seed germination and growth. An intense downpour following a dry spell can be ruinous, physically damaging young plants, washing away nutrients, and creating waterlogged conditions that can lead to crop failure. Farmers find themselves caught in a vicious cycle of facing both water stress and destructive floods within the same season, threatening their livelihoods and India's food security.
Why Our Cities Drown
Urban areas are uniquely vulnerable to this shift. Most Indian cities have drainage systems that were designed decades ago, built to handle a steady, predictable flow of water. These systems are completely overwhelmed by short, intense cloudbursts. When a month's worth of rain falls in a few hours, the water has nowhere to go. The problem is compounded by rampant, unplanned urbanisation, which has replaced permeable soil with impermeable concrete and asphalt, further increasing surface runoff and ensuring that even a statistically 'normal' or 'below-normal' season can bring devastating urban floods.
