Unseasonal Rains Defy Forecasts, Damage Crops, Disrupt Lives

The south-west monsoon arrived in Kerala on May 24, eight days earlier than usual and the earliest onset since 2009.

Most parts of the country had been reeling under heat waves in March and April, and the expectation was that it would get worse in May. In the event, most parts of the country did not see any significant or prolonged heat waves. Instead, there were widespread thunderstorms, even hailstorms, which brought down maximum temperatures and spared India a scorching May. However, the unseasonal downpours led to massive crop losses in states such as Tamil Nadu, Maharashtra, Telangana, Gujarat and elsewhere.

Now, as the country gears up for Kharif sowing, will May rains affect or decrease the spell of southwest monsoon in any way? Director General of the India Meteorological Department (IMD) M. Mohapatra answered in the negative and told IndiaSpend, “Long range, seasonal rainfall is not dependent on May rainfall. There is no 1:1 relationship.”

IMD has forecast an ‘above normal’ monsoon season this year. In a press conference on Tuesday, IMD forecast that monsoon will be particularly above normal over southern and central India, normal over northwest India, and below normal over northeast India. The month of June in fact has a forecast of 8% above normal rainfall (both forecasts with a margin of error of 4%). But there are bound to be variations.

Even last year, while India’s monsoon ended on a 6% surplus, there were large variations within regions and in between months. Within the monsoon months, there were variations in rainfall received, oscillating between deficit rain and surplus. Parts of Northeast India, Punjab, Bihar had seen deficient rainfall while Gujarat and Rajasthan saw surplus rainfall.

Heatwaves out, thunderstorms in

At the beginning of May, IMD had forecast hotter days and nights, and above-normal heatwave days in northwest, central and east India this month. While it had also forecast rainfall over the country as a whole to be above normal (or 9% more) of the ‘long period average’, so far, India’s monthly rainfall stands at 85.7% above normal instead (Data up to May 27).

It started in the very first week of May when many parts of the country started seeing widespread rainfall. There was a prolonged wet spell with moderate to severe thunderstorms, squally or gusty winds over northwest, central and eastern India. Heavy rainfall was recorded in parts of east Rajasthan, west Madhya Pradesh, Saurashtra & Kachchh on May 7 alone. That week had registered 35% more rainfall than was expected at this time of the year.

The wet spell did not stop there. In the second week also, India saw 20% more rain than usual, so much so that there was no heat wave recorded.

An important feature of this May’s weather has been the presence of gusty winds, hailstorms, thunderstorms with lightning, and dust storms. On ground, the unexpected arrival of these weather events led to chaos and disruption.

On May 20, Bengaluru city was lashed by heavy rain that killed three. Similar heavy rains were reported in Goa, Gujarat, Karnataka, Kerala, Tamil Nadu, Maharashtra and many other regions of India. In Maharashtra, there has been widespread rainfall in Marathwada, Vidarbha and Konkan areas that are typically heatwave prone. On May 2, Delhi recorded its second highest 24-hour May rainfall since 1901, killing four. Delhi also reported dust storms on May 21, and on May 25, downpour led to a portion of the canopy to collapse at the airport. May 7 was recorded as Mumbai’s second-wettest day in a decade, and the city is seeing its wettest May ever this year. Together, these extreme weather events have led to flight and train cancellations, traffic chaos, school closures, office disruptions and general disruption of normal life. These disruptions hit daily wage workers, small vendors, and local businesses the hardest, with many struggling to recover from days of halted operations and damaged infrastructure.

The extent and severity of the weather activity is reflected in the data. Central India has recorded five times its usual May rainfall (402% above normal) and south India has recorded more than two-and-a-half times the typical amount (165% above normal). Even Northwest India has recorded 24.7% more rainfall. So, while March and April rainfall stood at the deficient mark, May rainfall so far stands at a surplus of 85.7% (all figures up to May 27).

Together, the pre-monsoon season, which is March 1 to May 31 of a given year, now stands at a 28.3% surplus.

Parts of northeast India, Jammu & Kashmir and Ladakh, and Himachal Pradesh have however seen deficient pre-monsoon rainfall this year (March to May). Meanwhile, the Saurashtra and Kachchh region has seen 17 times the normal rainfall; the Gujarat subdivision has seen nearly 12 times; Konkan and Goa 19 times, and Vidarbha four times the normal rainfall this pre-monsoon season.

Raghu Murtugudde, retired professor at the Indian Institute of Technology-Bombay and emeritus professor, University of Maryland, said that the current thunderstorms (in May) are mostly due to the winds over the Arabian Sea meeting the winds from the Bay of Bengal, which is happening over peninsular and eastern India.

“That is firing up some rainfall events. Yes, it’s unusual for a pre-monsoon period. But we have had unusual sea surface temperature patterns in the tropical Pacific since 2023,” he said.

M. Mohapatra, the director general of IMD, called the May rainfall as ‘not such a regular occurrence.’

“Frequency of western disturbances has been higher this year. Consecutive WDs have brought all this rainfall activity, thunderstorms, hailstorm, fall in temperature etc. The more southern latitude echoes of these WDs also help incursion of moisture from Bay of Bengal and Arabian Sea. So that has caused this type of activity. It is a big country, there cannot be only one factor,” said Mohapatra.

When asked about the accuracy of IMD’s forecast for May, Mohapatra noted that the IMD had forecast above normal rainfall activity for the month of May.

“We gave spatial map which showed most parts of India to have above normal rainfall. Yes, we had forecast heatwaves, but that did not occur much.”

In a press conference on Tuesday, Mohapatra stated that the month of May saw five to seven western disturbances develop, become active and extend upto Central India. This was the primary reason behind thunderstorms in many parts of India, which in turn brought down temperatures.

Farmers hit

The southwest monsoon--when it is on time--is the lifeblood of Indian agriculture, supporting over 50% of the country’s farmland and contributing significantly to the economy through the Kharif crop season. This year, unseasonal rains in May have caused widespread crop losses in Tamil Nadu, Maharashtra, Gujarat and many other regions.

“It would usually not rain so much in May. We had a good crop this time around. But the weather got adverse. My banana trees already had fruits on them and they could not bear the impact of thunder and rain. It is all in God’s hands now,” said farmer Govind Kushwaha from Kushinagar district of Uttar Pradesh.

Kushwaha had planted bananas on one acre of land. Half his trees have fallen due to the unseasonal rain on May 22. His fruits are now impacted--the harvest will be less than expected, and quality of what remains will be compromised due to exposure to the rains, resulting in poor demand or low prices in the market.

Heavy rains led to losses of the banana crop in Uttar Pradesh’s Kushinagar district

Mango farmers are also badly hit in Uttar Pradesh. Awadh Mango Producers Bagwani Samiti Malihabad general secretary Upendra Singh said that farmers who had protected their mangoes using a technique called bagging (putting a net mesh over the fruit) managed to save their crop, but those who had not taken that precaution are facing heavy losses.

“This kind of weather is not good for horticulturalists. Thunderstorms have led to large scale losses in Lucknow, Meerut, Saharanpur, Aligarh, Jhansi and many parts of Western UP. These mangoes that have prematurely fallen have been damaged and will find no takers,” said Singh.

Western disturbances and their changing nature

Owing to India’s sheer size, the unusual rainfall activity in May cannot be attributed to one weather phenomenon alone. Multiple meteorological factors such as western disturbances, upper air cyclonic circulations, troughs and deep depressions, interaction of winds from the west and east are all contributing factors.

Western disturbances are storms that predominantly affect North India and Pakistan during winters. This year, these storms picked up from late January onwards. Western disturbances travel across the year but in different latitudes. They travel in lower latitudes during winters bringing significant amounts of rain and snow over North India. Meanwhile, in summers, these weather systems tend to travel in higher latitudes, confining snow and rainfall activities to the higher reaches of the region, according to research put together by Delhi-based think-tank Climate Trends.

However, climate change might be changing the very nature of these WDs. For example, WDs dumped a lot of rainfall over western Himalayas in April.

K.J. Ramesh, Former Director General of Meteorology, IMD had said in April, “Global warming has led to rapid warming of the Arabian Sea, which then emits more moisture northwards. Now, when the amplitude of Western Disturbances extends up to the North Arabian Sea, more moisture is fed into the system, resulting in intense weather activity over the hills.”

Scientists have warned of an increasingly erratic trend in Western Disturbances amid global warming. A.P. Dimri, Director, Indian Institute of Geomagnetism, said that increasing heat stress has also altered characteristics of Western Disturbances.

“Growing evidence shows that Western Disturbances are impacting weather outside the winter season, leading to extreme precipitation events. There is no doubt that increasing heat stress is the basis of everything, as it is generating more energy and at the same time pushing moisture upwards,” said Dimri.

These shifting weather patterns align with broader climate change trends, where rising global temperatures are intensifying extreme weather events, from unseasonal rains to altered storm cycles, posing new challenges for India’s climate resilience.

We welcome feedback. Please write to respond@indiaspend.org. We reserve the right to edit responses for language and grammar.