IMD says monsoon has arrived in India, days before schedule and earliest onset over Indian mainland since...

The southwest monsoon hit Kerala on Saturday (May 24), marking its earliest arrival over the Indian mainland since 2009 when it reached the southern state on May 23, the India Meteorological Department (IMD) said. Normally, the southwest monsoon makes its onset over Kerala by June 1 and covers the entire country by July 8. It starts retreating from northwest India around September 17 and withdraws completely by October 15.

The monsoon had set in over the southern state on May 30 last year; June 8 in 2023; May 29 in 2022; June 3 in 2021; June 1 in 2020; June 8 in 2019; and May 29 in 2018, IMD data showed. Data available since 1975 showed that the monsoon reached Kerala the earliest in 1990 (on May 19), 13 days before the usual date.

According to meteorologists, there is no direct relationship between the onset date and the total rainfall over the country during the season. The monsoon arriving early or late in Kerala does not mean it will cover other parts of the country accordingly. It is characterised by large-scale variabilities and global, regional and local features, an IMD official said.

The IMD in April forecast above-normal cumulative rainfall in the 2025 monsoon season, ruling out the possibility of El Nino conditions, which are associated with below-normal rainfall in the Indian subcontinent.

According to the IMD, rainfall between 96 per cent and 104 per cent of the 50-year average of 87 cm is considered 'normal'.

Rainfall less than 90 per cent of the long-period average is considered 'deficient'; between 90 per cent and 95 per cent is 'below normal'; between 105 per cent and 110 per cent is 'above normal'; and more than 110 per cent is considered 'excess' precipitation.

India saw 934.8 mm of rainfall in 2024, 108 per cent of the average and the highest since 2020. In 2023, it recorded 820 mm, 94.4 per cent of the average. In 2022, it saw 925 mm; 870 mm in 2021; and 958 mm in 2020, according to IMD data.

The monsoon is crucial for India's agriculture sector, which supports the livelihood of about 42 per cent of the population and contributes 18.2 per cent to the country's GDP. It is also essential for replenishing the reservoirs critical for drinking water and power generation across the country.

(This story has not been edited by DNA staff and is published from news agency PTI).