Earliest exit in 23 years: What made Delhi's 2025 monsoon season so unusual?

Delhi monsoon

The southwest monsoon withdrew from Delhi on Wednesday, marking its earliest departure from the capital in over two decades. The India Meteorological Department (IMD) confirmed the retreat on September 24, a day ahead of the usual schedule.

This year’s exit was the earliest since 2002, according to an analysis by HT. Last year, the monsoon withdrew significantly later, on October 2.

Despite the premature exit, the season delivered a surplus of rainfall. Delhi’s base weather station in Safdarjung recorded 902.6mm of rain, which is approximately 41% above the normal level of 640.4mm.

Why was Delhi's monsoon season short yet so soaking?



The monsoon arrived in Delhi on June 29, resulting in a season lasting 88 days. This was the ninth shortest duration since 2001.

However, the shorter season was remarkably consistent. Precipitation was recorded on 63 of the 88 monsoon days. This means it rained on about 71% of the days, the fourth highest proportion in the last 24 years.

The capital experienced three particularly heavy rainfall days, with deluges exceeding 68mm on July 29, August 9 and August 15. August was notably the wettest in 15 years.

What caused Delhi's consistent rainfall this year?



Meteorologists have attributed the excess rainfall to active and persistent weather systems. Mahesh Palawat, vice president of Skymet, explained the pattern, as cited by HT.

“This year, we had the monsoon trough persisting close to Delhi. This meant even without heavy rainfall spells, we had consistent light to moderate rain,” Palawat said.

The wet trend was not confined to the monsoon months. Delhi had its wettest May on record, and both June and July saw significant rainfall surpluses.

Which Delhi districts received the most rain?



Across Delhi’s districts, the average rainfall stood at 736.2 mm, a surplus of 37%. Central Delhi received the highest rainfall at nearly 950 mm. South Delhi recorded the least at 550.3 mm, but crucially, no district ended the season with a deficit.

The monsoon’s impact was felt across Northwest India, which recorded a 29% surplus in seasonal rainfall. The region was battered by heavy spells in August and September, leading to widespread flooding and landslides.

The IMD stated that the line of monsoon withdrawal has now passed through several states, including parts of Uttar Pradesh, Uttarakhand and Madhya Pradesh.

What weather can Delhi expect after the monsoon?



With the monsoon’s departure, dry northwesterly winds have begun to influence Delhi’s weather. This has led to a rise in temperatures.

On Wednesday, the maximum temperature settled at 35.4 degree Celcius, a degree above normal. Warm conditions are expected to persist for the coming days.

Meanwhile, the city’s air quality index was recorded at 120, placing it in the ‘moderate’ category. As per reports, this was a marginal improvement from the previous day.

The IMD has also issued warnings of heavy rainfall for several other parts of the country, including Odisha and Andhra Pradesh, due to a new weather system developing in the Bay of Bengal.