Dry desert winds flowing from the west and northwest of India may hold the key to predicting monsoon break periods, potentially giving farmers valuable time to prepare for rainfall deficits, according to a new study.
Published on February 10, 2026, in the Journal of Climate, the research analysed data spanning more than eight decades and found a strong link between dry air intrusions and pauses in the Southwest Monsoon.
The Southwest Monsoon accounts for more than 75% of India’s annual rainfall between June and September. However, it is marked by intermittent “break” periods days or weeks when rainfall significantly decreases across much of the country, while increasing in the Himalayan foothills and parts of the Northeast. These breaks can severely affect agriculture, particularly in rain-fed regions.
Researchers from the University of Reading and the Met Office in Exeter examined 188 monsoon break events between 1940 and 2023. Their findings suggest that dry winds begin entering India roughly a week before the midpoint of a break period, peaking in intensity two to three days before the middle of the dry spell.
When a break occurs, the monsoon trough shifts northwards from the Indo-Gangetic plains toward the Himalayan foothills, leading to reduced rainfall over central India. The study found that extended breaks defined as lasting seven days or more are associated with stronger and earlier dry wind intrusions compared to shorter breaks.
One recent example cited was the early 2024 monsoon season, when both the Bay of Bengal and Arabian Sea branches of the monsoon stalled in early June. Between June 1 and June 18, the country recorded a 20% rainfall deficit, disrupting sowing during the crucial kharif cropping season.
Historical data underscores the economic risks. In July 2002, two severe monsoon breaks led to a 50% monthly rainfall deficit, triggering drought conditions that reduced India’s GDP by an estimated 2%. In 1972, the monsoon experienced an extended 17-day break.
The researchers identified that these dry intrusions occur at mid-levels of the atmosphere and originate from arid regions west of the Hindu Kush mountains, near the borders of Afghanistan, Iran and Turkmenistan. As the dry air deepens and descends, it stabilises the troposphere, suppressing cloud formation and rainfall the meteorological driver behind monsoon breaks.
The team also developed a novel index to track the build-up of dry air before it reaches India. According to lead author Akshay Deoras of the University of Reading, monitoring these air masses days in advance could help farmers manage irrigation, adjust sowing schedules and prepare for potential water shortages.
Scientists concluded that the causal relationship between western dry winds and monsoon break periods offers a promising tool for strengthening early warning systems a development that could benefit millions dependent on monsoon rainfall for agriculture and water security.