Southwest monsoon is a four month long season over Indian region spanning from June to September. Monsoon as such being a complex phenomenon is also inherited with variety of phases ranging from active Monsoon to weak, lull and break etc. Southern parts of the country enjoy the complete four month duration of Monsoon, whereas northern region actively observe only about two months before it recedes in September.
Onset of Monsoon often takes a skewed shape and is rarely as per the normal dates over all parts of the country. The onset becomes further interesting, when this feature gets influenced by other global phenomenon like El Nino, La-Nina, ENSO , IOD and MJO etc.
It is observed that the Indian seas on either side of the coastline start becoming turbulent and rough during the pre-monsoon season and it continues to remain the same till mid July. Supposedly, the seas calm down relatively thereafter due to sustained Monsoon activity, altering the atmospheric parameters like temperature, humidity, winds etc.
State of the sea is being manifested as, Monsoon peaking at different times over different region. While the onset phase will see the Monsoon peaking over Kerala in June, Konkan and Goa, on the other hand will observe maximum rains during July. Central, Eastern and most Western parts receive good rainfall in August. Rainfall in September over various parts is in accordance with the withdrawal dates from the respective zones.
Here is a table showing the average monthly rainfall figures of some important cities.
| Cities | June Rainfall | July Rainfall | August Rainfall | September Rainfall |
| Kochi | 705 mm | 593 mm | 403 mm | 280 mm |
| Trivandrum | 330 mm | 188 mm | 152 mm | 169 mm |
| Kottayam | 653 mm | 539 mm | 415 mm | 275 mm |
| Mumbai | 523 mm | 800 mm | 530 mm | 312 mm |
| Mangalore | 1044 mm | 1104 mm | 734 mm | 253 mm |
| Nagpur | 166 mm | 288 mm | 275 mm | 171 mm |
| Ahmedabad | 95 mm | 281 mm | 235 mm | 96 mm |
| Delhi | 77 mm | 214 mm | 253 mm | 121 mm |
| Chandigarh | 145 mm | 280 mm | 307 mm | 133 mm |
| Allahabad | 127 mm | 265 mm | 279 mm | 204 mm |
| Bhubaneswar | 205 mm | 326 mm | 392 mm | 235 mm |
| Bhopal | 148 mm | 372 mm | 403 mm | 181 mm |
| Jabalpur | 212 mm | 341 mm | 433 mm | 172 mm |
Monsoon 2014 has behaved somewhat truant and left most meteorological agencies speculating its track and course during the four month long period. Onset dates, in any case are least correlated and also inconsequential of its further advancement and performance, as well, over different parts. However, this season, the onset has got systematically delayed right from Kerala to Mumbai and on to Kolkata and Delhi. One third of the season is coming to an end and the Monsoon still seeks some openings for entry in to significant portion of the country covering Gujarat, Rajasthan and parts of Madhya Pradesh.
Month of July inherited a rainfall deficiency of 43% from June and it continues to be same till date, for the country as a whole. The picture gets further scary with deficit mounting to 70% over central and northwestern parts. They also appear to be unsurmountable and therefore project reasonable chance of Meteorological drought in many of the sub- divisions.
