The delayed onset brings an end to speculation over its progress, with the India Meteorological Department (IMD) confirming that the monsoon has now advanced over the financial capital and the rest of Maharashtra. (PIC/ SATEJ SHINDE)

It's the city's latest monsoon arrival since June 25, 2023. (PIC/ SATEJ SHINDE)

The onset would also rank among the most delayed in the past decade, though it would still fall short of the June 25 arrivals recorded in 2019 and 2023, which remain among the latest onsets in recent years. (PIC/ ATUL KAMBLE)

In 2025, the southwest monsoon officially arrived in Mumbai on May 26, making it the earliest onset over the city in 75 years. This record-breaking arrival was 16 days ahead of the normal onset date of June 11, brought on by the rapid development of a low-pressure system in the Arabian Sea. (PIC/ ATUL KAMBLE)

The IMD said the Southwest Monsoon has further advanced into the remaining parts of the central Arabian Sea, some more parts of Maharashtra, including Mumbai, remaining parts of Telangana and Odisha, and some more parts of Chhattisgarh, Jharkhand and Bihar today, the 23rd of June, 2026. (PIC/ ATUL KAMBLE)

Conditions are favourable for further advance of the southwest monsoon into some parts of the North Arabian Sea and Gujarat, some more parts of Maharashtra and Chhattisgarh, and some parts of Madhya Pradesh during the next 2-3 days; remaining parts of Jharkhand and Bihar and some parts of Uttar Pradesh during the subsequent 3-4 days. (PIC/ ATUL KAMBLE)

IMD data from 1950 to 2025 highlights the wide variation in Mumbai's monsoon onset dates. (PIC/ ATUL KAMBLE)

Although June 11 is considered the normal onset date, the monsoon has arrived as early as May 26 and as late as June 25, underscoring the considerable year-to-year fluctuations in the city's rainy season. (PIC/ ATUL KAMBLE)

According to the data, the earliest monsoon onset was recorded on May 26, 2025, making it the earliest arrival in Mumbai since records began in 1950. Prior to that, the monsoon had arrived on May 29 in 1956, 1962 and 1971. (PIC/ ATUL KAMBLE)

On the other hand, the latest onset dates were recorded on June 25 in 1959, 2019 and 2023, while several other years saw the monsoon reach the city only during the third or fourth week of June. (PIC/ ATUL KAMBLE)

The data also highlights that monsoon arrival dates have shown no fixed pattern over the decades. In the 1950s, onset dates ranged from May 29 to June 21. The 1970s witnessed both very early arrivals, such as June 2 and June 3, and delayed arrivals extending to June 24. (PIC/ ATUL KAMBLE)

Similar fluctuations continued through the 1980s, 1990s and 2000s, with the monsoon arriving anywhere between late May and late June. (PIC/ ATUL KAMBLE)

In the last decade alone, Mumbai has witnessed substantial variation in onset dates—from June 20 in 2016 and June 25 in 2019 to the record early arrival of May 26 in 2025. The data underlines the highly dynamic nature of the southwest monsoon and the influence of multiple atmospheric and oceanic factors on its progress along India's west coast. (PIC/ ATUL KAMBLE)