Monsoon Arrives in Delhi and Mumbai Together for the First Time in 62 Years

In a rare weather occurrence, both Delhi and Mumbai experienced the arrival of the monsoon on the same day after a gap of 62 years . While the monsoon hit India's financial capital, Mumbai, 14 days later than usual, it arrived two days earlier than the normal date in the national capital, Delhi. This swift advancement of the rain-bearing system took place across central and northwest India within just four days, following a stagnant phase that lasted nearly two weeks.

The recent development of a cyclonic circulation over the Bay of Bengal, expected to move into Odisha, indicates that the monsoon has finally entered an active phase. This active phase is predicted to bring wet weather across southern, central, and northern regions of India over the next five to seven days.

The countrywide rainfall deficit in the month of June currently stands at 28% below normal as of June 25. However, the meteorological office forecasts a gradual reduction in this deficit over the coming week. The weather system is anticipated to cover more areas in the states of Gujarat, Rajasthan, Haryana, and Punjab, as well as the entirety of Jammu and Kashmir, within the next two days.

According to officials from the India Meteorological Department ( IMD ), the simultaneous arrival of the monsoon in Delhi and Mumbai last occurred on June 21, 1961. Normally, the monsoon reaches Mumbai 16 days before reaching Delhi. However, this year witnessed an unusual set of conditions that resulted in a weak onset over Kerala, and the Arabian Sea arm of the monsoon, which typically progresses into western India, remained sluggish.

Senior IMD scientist D Sivananda Pai explained, "The Arabian Sea arm remained weak due to cyclone Biparjoy taking away moisture from the system. At the same time, the remnant of the cyclone remained active as a low-pressure system over Uttar Pradesh and Madhya Pradesh for a number of days, drawing the Bay of Bengal arm towards the region."

Over the past few days, the monsoon had been gradually advancing into eastern and northern India from the Bay of Bengal, while the Arabian Sea arm remained stationary. However, this situation changed in the last couple of days with the formation of a cyclonic system over the northwest Bay of Bengal.

IMD Chief Mrutyunjay Mohapatra stated, "This disturbance is now expected to enter Odisha as a low-pressure system, and has energized the monsoon at both ends. A low-pressure system over the Bay of Bengal often strengthens the monsoon at the Arabian Sea end as well, due to stronger westerly wind flows. We expect active monsoon conditions to last for the next five to seven days."

The strengthening of the monsoon comes at a time when rainfall across the country in June has been inadequate. Apart from Gujarat and some parts of northern India, including Rajasthan, which experienced the impact of cyclone Biparjoy and its remnants, along with Assam and Meghalaya in the northeast, there is a significant rainfall deficit in the country.

The meteorological office expects the monsoon system to cover more areas in Gujarat, Rajasthan, Haryana, and Punjab, as well as the whole of Jammu and Kashmir, over the next two days. This convergence of the monsoon in both Delhi and Mumbai highlights the unusual weather patterns that have marked this year's monsoon season in India.