The Great Withdrawal: A Phased Exit
The monsoon's departure isn't like flipping a switch. It’s a gradual process that typically begins in the northwestern parts of the country and moves south-eastward over several weeks. The India Meteorological Department (IMD) has updated its normal withdrawal
dates, with the process starting from west Rajasthan around mid-September. This slow retreat means different parts of the country experience the shift at different times. While the north-west starts to dry out, the southern peninsula might still see considerable rainfall. According to the latest IMD forecasts for 2026, the withdrawal is expected to be on time, beginning around September 17.
The 'Second Summer' Phenomenon
One of the most noticeable effects of the monsoon withdrawal is a rise in daytime temperatures. As the dense cloud cover that defined the monsoon months dissipates, more direct sunlight reaches the ground, causing temperatures to climb. This period is often referred to as the 'second summer' or 'October heat', although the warming trend begins in September. For September 2026, the IMD has forecast that maximum temperatures are likely to be above normal for most of the country. This is linked to the prediction of below-normal rainfall for the month, which means fewer clouds and rain showers to cool the air during the day.
Drier Air and Cooler Nights
While days get hotter, the nights often bring a welcome change. The reduction in cloud cover not only lets the sun in during the day but also allows heat to escape more effectively at night. This leads to a larger diurnal temperature range—the difference between the day's high and night's low. Furthermore, as the moisture-laden monsoon winds retreat, the air becomes significantly drier, leading to a noticeable drop in the sticky, oppressive humidity that characterises the rainy season. This combination of warmer, sunnier days and cooler, more comfortable nights is a hallmark of the post-monsoon transition. However, for September 2026, the IMD notes that minimum temperatures are also expected to be above normal for most regions.
The Role of El Niño in 2026
This year's weather patterns are heavily influenced by strong El Niño conditions in the Pacific Ocean. El Niño, a phenomenon involving unusually warm ocean temperatures, is often associated with suppressed monsoon rainfall in India. The IMD has noted that these conditions strengthened in August—which was the hottest August since 1901—and are expected to continue into September. This is a key reason behind the forecast for below-normal rainfall (less than 91% of the long-term average) and warmer-than-average temperatures for September 2026. The influence of El Niño adds another layer of certainty to the prediction of a hotter, drier end to the monsoon season.
Regional Weather Variations
The effects of the monsoon's withdrawal are not uniform across India. As the withdrawal line moves from northwest to southeast, northern states will experience clearer skies and drier weather first. In contrast, some parts of eastern, central, and peninsular India may continue to experience rainfall. The Bay of Bengal can also become active with cyclonic storms during this period, particularly in October and November, which can bring heavy rainfall to the eastern coast. For September 2026, while the overall trend is drier, a low-pressure system over eastern India is expected to bring rain to regions like Odisha and Jharkhand early in the month.
