Multi-day extreme precipitation caused major floods in India during summer monsoon of 2024

Climate change has increased the risk of extreme precipitation and flooding in India. During the 2024 summer monsoon season, three major extreme precipitation events occurred across the western, southern, and northern states of India, leading to widespread flooding in these regions. We examine the causes and impacts of extreme precipitation and flood events using a combination of observational data, reanalysis datasets, and hydrological models. In all the three regions, extreme rainfall occurred immediately after multiday continuous precipitation, resulting in catastrophic flooding. The 3-day extreme precipitation that caused flooding in the three regions had return periods of more than 75 years, 100 years, and 200 years, respectively. The primary moisture source for the Gujarat floods (western India) was the Arabian Sea, while the floods in Andhra Pradesh and Telangana (southern India) were driven by dual moisture advection from both the Arabian Sea and the Bay of Bengal. For the floods in northern India, the dominant moisture sources were recycled land moisture and southwest moisture transport from the Arabian Sea. These moisture inflows, combined with favorable atmospheric conditions and pre-existing saturated soils, resulted in severe flooding across all regions. Our findings underscore the escalating challenge of managing such extreme events as their frequency and intensity rise with global warming.