Heavy showers ahead: IMD warns of above-normal rainfall in India this October

India is expected to receive 15 per cent more rainfall than normal in October, following a bountiful monsoon season, the India Meteorological Department (IMD) announced on Tuesday. IMD Director General Mrutyunjay Mohapatra said maximum temperatures in October are likely to be above normal in most parts of east-northeast and northwest India, while other regions of the country may experience normal to below-normal maximum temperatures.

Mohapatra added that most parts of the country are expected to see above-normal rainfall during the post-monsoon season (October to December), except for some areas in northwest India, where rainfall is likely to be normal to below-normal.

The IMD also stated that the Northeast Monsoon, which spans from October to December, will bring above-normal rainfall to southern peninsular India. This includes Tamil Nadu, Coastal Andhra Pradesh, Rayalaseema, Kerala, and South Interior Karnataka, where rainfall is expected to exceed 112 percent of the long-period average (LPA) based on data from 1971 to 2020.

The LPA for the October to December season over South Peninsular India is approximately 334.13 mm, and the country is likely to receive above-normal rainfall in October, with expectations of more than 115 percent of the LPA, which is 75.4 mm, Mohapatra explained. He attributed this to the development of low-pressure systems in the Bay of Bengal and the Arabian Sea, along with other large-scale atmospheric processes and intra-seasonal variability. However, some areas in northwest India, and isolated pockets in the southern peninsula and northeast India, may see normal to below-normal rainfall in October.

In the broader context, the IMD also noted that India’s four-month monsoon season ended on a positive note, with the country recording 8 percent more rainfall than the normal. India recorded 937.2 mm of rainfall, which is 8 per cent more than the normal of 868.6 mm for the entire monsoon season.

Despite the surplus rainfall, the IMD reported that the monsoon season in east and northeast India faced challenges, with the region receiving 20 percent less rainfall than normal, amounting to 1089.9 mm compared to the normal of 1367.3 mm. States like Bihar, Arunachal Pradesh, Assam, and Meghalaya experienced deficient rainfall in three of the four monsoon months. 

"Rainfall over east and northeast India this monsoon season was the second-lowest since 1901," Mohapatra noted, adding that studies indicate a decreasing trend in rainfall over this region in recent years.

On the other hand, northwest India recorded a significant increase in rainfall, receiving 747.9 mm, which was 27.3 percent more than the normal of 587.6 mm. This was the highest rainfall in the region since 2001 and the sixth-highest since 1901. Mohapatra said that all districts in northwest India had above-normal rainfall in June, August, and September.

Central India saw 15.1 percent more rainfall than the normal, recording 1125.3 mm, while the southern peninsula recorded a 9.9 percent surplus, receiving 716.2 mm of rainfall during the season.

(With inputs from PTI)