https://www.skymetweather.com/content/weather-news-andanalysis/el-nino-iod-and-mjo-all-in-favour-of-timely-onset-of-northeast-monsoon-2019/

With the beginning of October, countdown to onset of Northeast Monsoon has also begun. And, the good news is that the season is likely to kick start on time. Normal date of commencement of Northeast Monsoon is around October 20 (with an error margin of +/- 5 days). During the last 12 years, it has been seen that onset of Monsoon has been between October 22-28 on most of the occasions.
It is very rare that we see Monsoon rains arriving in November, however 2018 was one such case where in Monsoon had begun its journey on November 1. This was account of formation of two severe cyclones – Titli and Luban that had collided with the onset of Northeast Monsoon. Thus, it stalled the process of withdrawal of Southwest Monsoon.
The three-month long season does not begin its journey before the withdrawal of Southwest Monsoon. To be precise, Northeast Monsoon and Southwest Monsoon do not co-exist. Although this year, Southwest Monsoon has started retreating quite late by October 9, but weather conditions are still ripe for the timely onset of Northeast Monsoon.