The India Meteorological Department declared on Thursday that the southwest monsoon had arrived over Kerala, two days before the season’s normal onset date.

The weather agency on Monday said that it expects India to receive above-normal rainfall during the four-month long rainy season this year. This would be around 880.6 mm of precipitation, or 106% of India’s long period average (the mean seasonal rainfall between 1971 and 2020).

The southwest monsoon season generally begins in June and starts to retreat by September.

The official declaration of the start of this year’s season comes after a fortnight of heavy rainfall in Kerala, Manorama reported.

According to the India Meteorological Department’s data as of Thursday, more than 60% of the weather agency’s rain gauges in Kerala had already recorded precipitation of 2.5 mm or more over two consecutive days since May 10 – the criteria to declare the onset of the rainy season.

This year marks the first time in nearly a decade that the weather agency has predicted above-normal rainfall in its long-range forecast for the season.

The central and southern peninsular regions of the country are likely to get above-normal rainfall while normal rainfall is predicted in northwest India and below normal over the northeast regions, it said.

While above-normal rainfall is 106% of the long period average, normal rainfall is the range between 92% to 108% of the measure. Rainfall under 94% is classified as below normal.

The weather agency also predicted above-normal rainfall over the Monsoon Core Zone, which comprises most of the rainfed agriculture areas of the country, during the season.

On May 19, the India Meteorological Department announced the onset of the southwest monsoon over southern Bay of Bengal, the Nicobar Islands and the South Andaman Sea.

Also read: Why climate change is making it harder to forecast the monsoon accurately