The normal date of the onset of the southwest monsoon over Kerala, the southern tip of India, is 1 June. The monsoon takes about a month and a half to travel from Kerala to west Rajasthan and it does not advance into the country at a constant speed. See map below:

1.4.1 Onset Dates

The southwest monsoon arrived over Kerala on 29 May 2011. If you want to know how the southwest monsoon has been progressing this year over India, the best way is to visit the official web site of the India Meteorological Department (IMD) at and click on “Monsoon”. On the Monsoon page, you will find a variety of current and climatological information about the monsoon as well as forecasts. 

Another good site is Monsoon On Line hosted by the Indian Institute of Tropical Meteorology, Pune, on which you can see daily, weekly and seasonal rainfall statistics of the southwest monsoon rainfall over India and the current satellite imagery.