NEW DELHI: The four-month Southwest Monsoon season came to an end in the country, finishing on September 30, with an overall surplus of 8 per cent rainfall.
On Tuesday, the India Meteorology Department (IMD) indicated that there is “very likely” to be continued prolonged wet conditions in themonths ahead, with it being expected that there will be above-normal rainfall in October. The seasonal rainfall was above normal (>104% of LPA) as per the IMD forecast.
“India is highly likely to experience rainfall in excess of 115 per cent of the Long Period Average (LPA) of 75.4 mm for October,” said IMD Director General Mrutyunjay Mohapatra. “During the same month, we expect that India will see normal to below normal maximum temperatures in other parts of the country,” Mohapatra said, indicating that cooler-than-usual conditions could accompany the wet weather in many areas of India.
IMD’s forecasts suggested that most of India will be subject to normal to above normal rainfall throughout the month of October. Specifically, parts of Northwest India, extreme Southern Peninsular India, and pockets of the Northeast of India are expected to experience below normal rainfall.
India experienced 937.2 mm of rainfall during the June-September season, against an LPA of 868.6 mm, for a surplus of 8 per cent. Mohapatra described the season as “very successful” but acknowledged that it was marred by weather disasters such as cloudbursts, landslides, and flash floods across hilly and vulnerable regions.
The monsoon’s bounty, however, was unevenly distributed. While Northwest India benefited from 747.9 mm of rainfall, 27.3 per cent above its LPA of 587.6 mm, East and Northeast India faced a severe shortfall. The region received only 1,089.9 mm of rainfall, 20 per cent below its normal of 1,367.3 mm.
“This year’s rainfall over East and Northeast India was the second-lowest since 1901, with only 2013 recording lower rainfall,” Mohapatra noted. He also pointed out a concerning trend: “Rainfall over this region has been deficient in many years. Studies show a decreasing pattern over the last two decades.”
States like Bihar, Arunachal Pradesh, Assam, and Meghalaya bore the brunt of the deficit, experiencing below-normal rainfall in three of the four monsoon months.
Looking ahead, the IMD has predicted a wet transition into the post-monsoon (October–December) season. Most of India is expected to receive above-normal rainfall, except in parts of Northwest India, extreme South India, and isolated areas of the Northeast.
For the southern peninsula, which depends heavily on the Northeast Monsoon rains, the forecast is especially encouraging. Seasonal rainfall in Tamil Nadu, Puducherry, Coastal Andhra Pradesh, Rayalaseema, Kerala, and South Interior Karnataka is projected to exceed 112 per cent of the LPA.
The IMD attributed their prognosis to a combination of factors, including the development of low-pressure systems over the Arabian Sea and Bay of Bengal, intra-seasonal variabilities, and larger-scale climatic processes.
The above-normal rainfall in many regions over the country will have a positive impact on agriculture, raising water levels in reservoirs, and will also support hydropower generation. However, the uneven distribution raises questions of regional water security, particularly for the excessively deficit-hit East and Northeast.
The IMD also noted that the withdrawal of the monsoon is expected to be delayed this year, and grant wet conditions are likely to prolong into early October. On the one hand, this may assist farmers with their sowing for rabi crops; on the other, it raises the chance of waterlogging in already saturated regions.
While the monsoon transitions into the post-monsoon phase, policymakers and disaster management officials will have an advantage to keep watch and monitor, especially in states prone to floods and landslides. Experts bring an advantage that above normal rainfall could help with short-term water shortages, but warn that the rapidly increasing frequency of extreme weather shows a greater necessity for climate-resilient infrastructure, along with adaptive agricultural systems.
An analysis:
Seasonal rainfall over Northwest India, Central India, South Peninsula, and Northeast India were 127%, 115%, 110% and 80% of the respective LPA.
Rainfall over Northwest India was 747.9 mm which is highest since 2001 and 6th highest since 1901, However, Rainfall over East & Northeast India was 1089.9 mm which is 2nd lowest since 1901.
The southwest monsoon seasonal (June to September) rainfall over the monsoon core zone, which consists of most of the rain-fed agriculture regions in the country, received 122% of LPA.
Out of the 36 meteorological subdivisions, 2 subdivisions, covering 10% of the country’s total area, experienced large excess rainfall. Twelve subdivisions, constituting 35% of the area, received excess rainfall, while 19 subdivisions, representing 46%, recorded normal rainfall. The remaining 3 subdivisions,
Arunachal Pradesh, Assam & Meghalaya, and Bihar accounting for 9% of the total area, experienced deficient rainfall during the season.
Monthly rainfall over the country as a whole was 109% of LPA in June,105% in both July and August and 115% of LPA in September.
The southwest monsoon advanced over the South Andaman Sea and Nicobar Islands on 13 May 2025, nearly nine days ahead of the normal schedule. It arrived in Kerala on 24 May 2025, ahead of the usual onset date of 1 June, and covered the entire country by 29 June 2025, earlier than the normal date of 8
July. The monsoon withdrawal began from west Rajasthan on 14 September,
advancing by 3 days.
There were Seven Monsoon Depressions formed during the season, out of that one intensified in to Deep Depression Category. There were 69 Low Pressure System Days against its normal 55 days.
The seasonal forecast issued by IMD for the SW monsoon season rainfall was accurate, including the monsoon onset forecast over Kerala and ENSO and IOD forecast.
The Southwest Monsoon advanced into parts of the South Bay of Bengal, South Andaman Sea, Nicobar Islands, and some areas of the North Andaman Sea on 13 May 2025, ahead of the normal date of 19 May. By 19 May, it further progressed into parts of the Southeast Arabian Sea, South Bay of Bengal, South Arabian Sea, Maldives, Comorin area, Central Bayof Bengal, and Northeast Bay of Bengal.
On 24 May 2025, the monsoon advanced rapidly over the remaining parts of the South
Arabian Sea, West central and East central Arabian Sea, entire Lakshadweep region, Kerala,
Mahe, parts of Karnataka, Maldives, Comorin area, many parts of Tamil Nadu, Southwest and
Eastcentral Bay of Bengal, West central and North Bay of Bengal, and some parts of Mizoram.
The monsoon set in over Kerala on 24 May, eight days earlier than the normal date of 1 June,
marking the earliest onset since 2009.
Following its onset in Kerala, the Southwest Monsoon progressed swiftly, covering
South India and Northeast India by 29 May. After a brief pause, further advance resumed on
16 June. By 26 June, most parts of the country were covered except for some areas of
Northwest Rajasthan, West Uttar Pradesh, South Punjab, South Haryana, and Delhi. The
monsoon covered the entire country by 29 June 2025, nine days ahead of the usual date of 8
July.
The withdrawal of the Southwest Monsoon 2025 commenced on September 14, 3
days earlier than its normal date of September 17th September 2025.
