India's monsoon season is experiencing a mixed bag of weather patterns, with significant rainfall deficits in some areas despite an overall surplus in precipitation. While floods in Assam and heavy rainfall-induced landslides in Kerala have drawn global attention, 25% of the 36 meteorological subdivisions in India are still grappling with a rainfall deficit halfway through the season.
"India July rain recorded at 9% above normal," India Meteorological Office Chief Mohapatra said at the press briefing on Thursday.
The country saw 306.6 mm rainfall in July compared to the usual 280.5 mm, with a cumulative precipitation of 453.8 mm against the normal of 445.8 mm since June 1. This reflects a surplus of 2%, according to India Meteorological Department data. However, the distribution of rainfall in July was uneven, both spatially and temporally.
Regions such as east Uttar Pradesh, Bihar, Jharkhand, gangetic West Bengal, and parts of the northeast have recorded significant rainfall deficits. The deficit in Haryana, Punjab, Himachal Pradesh, and Jammu and Kashmir ranges from 35% to 45%.
Rainfall deficit in east and northeast India increased from 13.3% on June 30 to 19% on July 31, with the region recording 610.2 mm of rainfall against the normal of 752.5 mm so far this monsoon season. Northwest India recorded 182.4 mm of rainfall in July, compared to the normal 209.7 mm, a deficit of 13%. The region has received 235 mm of rainfall so far this monsoon season, against the normal of 287.8 mm, a shortfall of 18%.
In contrast, central India received 33% more rainfall than normal in July, with 427.2 mm of precipitation compared to the usual 321.3 mm. Overall, the region has recorded 574.2 mm of rainfall so far this monsoon season, against the normal of 491.6 mm. The southern peninsula received 36% more rainfall in July, with 279.2 mm compared to the usual 204.5 mm. Overall, it has recorded 463.1 mm of rainfall so far this monsoon season, against the normal of 365.5 mm, an excess of 27%.
The IMD data indicates that the rainfall deficit in gangetic West Bengal stands at 40%, with all 15 districts recording below-normal precipitation. Jharkhand has received 41% less rainfall than normal, with all 24 districts in the deficient category. Odisha has a rainfall deficit of 11%, with 12 of its 30 districts in the deficient category. All but five districts in Bihar have recorded a significant rainfall deficiency, resulting in an overall 36% deficit for the state so far this monsoon season.
The rainfall shortage in Uttar Pradesh and Uttarakhand stands at 15% and 4%, respectively. 19 out of 22 districts in Haryana have recorded below-normal rainfall, with the overall deficit standing at 43%. Punjab has a 45% deficit, with only three of the 22 districts recording normal rainfall. Jammu and Kashmir, which has been experiencing a rare and severe heat wave, has recorded 37% below-normal rainfall.
The IMD had earlier predicted normal to above-normal rainfall over most parts of the country, except for many parts of northeast India and some parts of northwest, east, and southeast peninsular India. The weather department expected above-normal rainfall activity in Himachal Pradesh, Uttarakhand, Jammu and Kashmir, and the foothills of the western Himalayas.
Kerala, where heavy rainfall-induced landslides have claimed over 150 lives, has received 4% less rainfall than usual. Delhi, where 15 people have died in rain-related incidents, has received 8% below-normal rainfall. In central and west India, Goa received 50% surplus precipitation, Maharashtra 39%, Gujarat 23%, and Madhya Pradesh 7%. In southern India, Tamil Nadu received 56% surplus rainfall, Andhra Pradesh 43%, Karnataka 33%, and Puducherry 20%.
The Indian monsoon is characterised by inherent fluctuations and changes over time due to various natural factors, known as natural variability. However, research shows climate change is making the monsoon more variable, leading to more extreme weather and dry spells.
According to the IMD, below-normal rainfall is expected in northeast India during the entire season, normal in the northwest, and above-normal in central and south peninsular regions of the country.
India's core monsoon zone, covering most of the rain-fed agricultural areas, is predicted to receive above-normal rainfall this season. The monsoon is critical for India's agricultural landscape, with 52% of the net cultivated area relying on it.
Weather agencies expect La Niña conditions to set in by August. La Niña, characterised by cooler-than-normal waters in the central Pacific Ocean, is associated with plentiful rainfall in the Indian subcontinent during the monsoon season.
(With inputs from PTI).