What Is Monsoon Withdrawal?
The monsoon withdrawal is not like flipping a switch. Instead, it is a gradual, weeks-long process where the moisture-laden southwesterly winds that bring rain to the subcontinent begin to weaken and retreat. The process is officially declared by the India
Meteorological Department (IMD) based on specific criteria, including a cessation of rainfall for five continuous days, the establishment of an anticyclone (a high-pressure system) in the lower atmosphere, and a significant reduction in moisture. This retreat typically begins in the northwestern parts of India and slowly moves southeast across the country, taking about five to six weeks to complete. This means one part of the country can be in a post-monsoon phase while another is still experiencing active monsoon conditions.
When Does It Start This Year?
While fresh satellite imagery shows vast, cloud-free stretches across northwest and central India, the official withdrawal has not yet begun as of September 8, 2026. Forecasters indicate that the formal process is expected to start after September 15. Weather models project that atmospheric conditions will become increasingly favourable for the retreat during the second half of the month, with an anticyclonic circulation expected to strengthen over northwest India around September 21. This is slightly later than the normal withdrawal date of September 17, a date that was itself revised from September 1 in 2020 to reflect a trend of delayed withdrawals. However, active monsoon conditions are still predicted in some areas, with the IMD forecasting fairly widespread rains over states like Himachal Pradesh and Uttarakhand through September 13.
The Journey Across India
The withdrawal's journey is a staggered one. It starts from the extreme northwestern state of Rajasthan in mid-September. From there, the line of withdrawal moves progressively southeast. By mid-October, it typically withdraws completely from the northern half of the peninsula. The final retreat from the southern peninsula is often more rapid, with the monsoon leaving the entire country by early December. During this time, the wind system over India reverses. The moist southwesterly winds are replaced by drier northeasterly winds blowing from the land towards the sea, marking the transition to the dry season for most of the country.
What Changes in the Weather?
As the monsoon clouds disappear, skies become clearer and sunnier. This often leads to a temporary rise in daytime temperatures, a phenomenon popularly known as 'October heat'. While days are warm, nights begin to cool down. Humidity levels drop, and the incessant rain gives way to dry weather across North and Central India. However, this period also brings its own risks. The Bay of Bengal becomes a hotspot for the formation of tropical cyclones during October and November, which can bring intense rainfall and strong winds, particularly to the eastern coast.
Impact on Agriculture and Water
The timing and nature of the monsoon's retreat are critical for Indian agriculture. A delayed withdrawal with excess September rain can damage standing Kharif (summer) crops like rice, soybeans, and cotton that are nearing harvest. However, it is beneficial for the upcoming Rabi (winter) season, as it helps replenish reservoirs and ensures adequate soil moisture for planting crops like wheat and chickpeas. The 2026 monsoon season has been marked by erratic behaviour, with the country facing an overall rainfall deficit of 14% as of early September, despite some regions experiencing floods. A drier-than-usual September could impact soil moisture and potentially affect the planting of winter crops.
The Northeast or 'Retreating' Monsoon
For Peninsular India, the end of the Southwest Monsoon is not the end of the rains. As the main monsoon system withdraws, it gives way to the Northeast Monsoon, also known as the retreating monsoon. This season, from October to December, is the primary rainfall period for states like Tamil Nadu, which receives almost half its annual rainfall during this time, as well as for parts of Andhra Pradesh and Karnataka. The change in wind direction from southwest to northeast brings moisture from the Bay of Bengal to these southern states, ensuring that while one part of India dries out, another prepares for its main rainy season.
