Data Bytes

While the majority of India's rain falls during its south-west monsoon, the pre-monsoon season (March-May) also accounts for a share of the precipitation. The 2025 pre-monsoon season in India stands out as one of the most extreme on record.

Three key rainfall indicators-total precipitation, maximum one-day rainfall, and maximum five-day rainfall-capture the severity of short-duration rainfall events. Total precipitation is the cumulative rainfall received during the pre-monsoon season. Maximum one-day rainfall represents the highest rainfall recorded in a single day during the season. Maximum five-day rainfall measures the highest rainfall accumulated over any consecutive five-day period.

In 2025, the maximum one-day and maximum five-day rainfall both recorded their highest values since 1951. Together with the near-record total seasonal precipitation, these indicators suggest that pre-monsoon rainfall is becoming both heavier and more concentrated during heavy spells. All three indicators show an upward trajectory over the past seven decades, with the sharpest increases occurring after 2015.

Historically, the pre-monsoon was relatively drier, averaging just 10-15 rainy days and 20-50 mm of cumulative rain at the national level. Recently, however, both rainfall frequency and totals have increased, with 2025 recording seasonal precipitation of 126 mm - the second-highest value since 1951.

The increasing concentration of rainfall into one-day and multi-day events has important implications for disaster risk, agriculture and urban infrastructure.

Read about the seasons in India that have got wetter and drier.