Below-Normal Monsoon Forecast Highlights Climate Change-Induced Extreme Rainfall Risks

Indian Express - Explained · 27 Apr 2026 · 2 min read
Prelims · Environment Mains · GS3 Environment and biodiversity High relevance

IMD predicts 92% of normal monsoon rainfall for 2024, but increasing frequency and intensity of extreme rainfall events pose significant disaster risks, linked to climate change and urban planning failures.

Key points

India Meteorological Department (IMD) forecasts 92% of Long Period Average (LPA) rainfall for 2024 monsoon season, classified as 'below-normal', but this masks regional variations and extreme weather risks.

Extreme rainfall events (above 21 cm/24 hours) have increased from 64 in 2008 to 181 in 2024, with annual counts consistently exceeding 100 since 2017, indicating climate change impacts on monsoon patterns.

[GS3-Environment] The Kedarnath tragedy (2013) marked the start of a decade where India faced at least one major rainfall disaster annually, including urban floods in Chennai (2015) and Kerala (2018), showing climate vulnerability.

Urban flooding in major cities is exacerbated by poor planning, construction on floodplains, and loss of water bodies, but unprecedented rainfall intensities are increasingly the trigger, as seen in Jammu & Kashmir's 2014 floods (280 deaths).

[GS1-Geography] The Western Ghats and Himalayan regions are particularly vulnerable to extreme rainfall events due to orographic lifting, with Kerala (2018) receiving its highest rainfall since 1931.

IMD's forecasting limitations cannot reliably predict rainfall intensity differences between 250mm and 500mm due to weather system chaos, though better modeling can improve granularity.

Climate change is increasing monsoon uncertainty by making extreme events more frequent and intense globally, not just in India, challenging traditional disaster preparedness models.

Way Forward: Strengthen urban drainage masterplans with climate-resilient designs, enforce strict regulations on floodplain construction, expand real-time weather monitoring networks, and integrate climate projections into state disaster management plans.

Key terms

Long Period Average (LPA)

IMD's 50-year average rainfall (88cm for 1971-2020) used as monsoon benchmark. Below-normal (90-96% LPA) and deficient (<90%) classifications trigger agricultural contingency plans under the National Rainfed Area Authority and crop insurance schemes like PMFBY.

India Meteorological Department (IMD)

India's national meteorological service under MoES, responsible for weather forecasting and monsoon prediction. Its classifications (normal, below-normal, etc.) based on Long Period Average (LPA) of 88cm rainfall are critical for agricultural planning and disaster preparedness under the National Disaster Management Act, 2005.

Extreme Rainfall Event

Defined by IMD as rainfall exceeding 204.5mm (21cm) in 24 hours. These high-intensity, short-duration events have increased due to climate change, causing disproportionate damage despite contributing less than 0.1% of total rainfall, challenging GS3 disaster management strategies.

Urban Flooding

Inundation in cities caused by extreme rainfall overwhelming drainage systems, compounded by impermeable surfaces and encroachment on natural waterways. The 74th Constitutional Amendment mandates urban local bodies to manage drainage, but lack of integration with climate adaptation plans exacerbates risks.