Climate Change and a Changing Monsoon

How climate change is making Indian rainfall more erratic, with more extreme downpours and longer dry spells, and what this means for farming and cities.

The monsoon has always varied from year to year. Climate change is changing its behaviour in ways that matter for the economy.

What scientists observe

More extreme rainfall events: a study led by Roxy Mathew Koll in 2017 found a roughly threefold increase in widespread extreme rain events over central India between 1950 and 2015.
Fewer moderate rainy days in some regions, with rain concentrated in intense bursts.
Longer dry spells within the monsoon season.
Shifts in timing and regional patterns.
Warming that increases evaporation and heat stress.

Why this matters for farming

Intense downpours cause runoff and soil erosion rather than soaking into the ground.
Long dry spells during critical growth stages cut yields.
Unseasonal rain and hailstorms can damage ripening crops, as in parts of India in March 2023.

Even if total rainfall stays similar, more erratic rain increases farmers’ risk.

Why it matters for cities

Urban floods: cities like Mumbai, Chennai and Bengaluru have experienced severe flooding from extreme rainfall, overwhelming drainage.
Landslides in hilly regions, such as the Himalayas and Western Ghats.

Economic costs

Extreme rain events damage crops, homes, roads and power lines, and disrupt business. Insurance losses and relief spending rise.

Adapting

Water harvesting and storage to capture intense rain.
Drought- and flood-tolerant crop varieties.
Better drainage and flood planning in cities.
Improved forecasts of extreme events.
Crop insurance and social protection.
Diversifying incomes beyond rainfed farming.

The two downpours

A farming district receives its normal seasonal total, but most of it falls in two extreme downpours in July, followed by a month-long dry spell. Fields flood, then crops wilt. The seasonal statistics look normal, but the harvest is poor.

Thinking climate change only means less rain

Climate change is making rainfall more erratic, with more extreme downpours and longer dry spells, even where totals change little.

Key takeaways

Extreme rain events over central India roughly tripled between 1950 and 2015.
Rain is becoming more intense and erratic, with longer dry spells.
Erratic rain raises risks for farmers and flooding in cities.
Water harvesting, resilient crops, better drainage and insurance help adaptation.