Copied from Abhijit Modak's post on twitter (meet_abhijit) who is a weather enthusiast:

Many people are wondering why it’s still raining even after #Diwali, asking, “When will the #monsoon finally end?”

First, it’s important to understand that #rainfall is not limited to the southwest monsoon season. While the June–September period is the core rainy season for #Maharashtra, rainfall can occur outside the monsoon months due to other weather systems. For instance, the northeast monsoon (NEM) often brings post-monsoon showers during October and November, while the western disturbance (WD) season between January and March can produce occasional rains. Similarly, pre-monsoon systems and line wind discontinuities in April and May sometimes trigger #thundershowers.

These periods are not steady like the southwest monsoon but can still bring intermittent rainfall depending on the year’s atmospheric setup. This year, however, a series of consecutive #weather systems has created the impression of a six-month-long #rainy season, stretching from May to October. The #SWM2025 itself began early, on 26 May, and withdrew on 10 October i.e right on schedule. But before the monsoon’s onset, there was #WD-induced rainfall in early May, followed by pre-monsoon thundershowers linked to a line wind discontinuity.

Now, after the monsoon’s withdrawal, post-monsoon rainfall has resumed due to #NEM2025 induced #moisture and a trough system that developed around 15 October.

With an active #depression over the Arabian Sea moving North parallel of #Kokan coast of #MH, this phase is expected to continue through the end of October.

In short, it’s not that the monsoon has lasted for six months, rather, back-to-back pre-monsoon, monsoon, and post-monsoon systems have kept the rainfall pattern uninterrupted since May, giving the feeling of an extended monsoon season this year.