The due date for monsoon in Mumbai is 10th of June but as monsoon has taken a giant leap from its 1st and 2nd of June position over Mangalore which is 602 km from Ratnagiri, there is strong possibility that it could reach Mumbai three days before the due date. Also, southwest monsoon traditionally reaches the city one week after its first appearance near Kerala coast.
After reaching the city, southwest monsoon gives almost 500 mm of rain during the month of June. The average rainfall for the city for the month is 523 mm. The month has 14.5 rainy days as an average.
Monsoon was one of the weakest last year in a decade as only 298.5 mm of rain occurred in Mumbai during the month of June. The year 2008 remains the wettest in the last 10 years when the city was lashed with over 800 mm of rain during the same month.
Temperature vs Rain during June
Going by the trend in the month of June it is observed that if there is no rain in first half of the month the maximum temperature scales above 40 degrees. The trend also suggests that if there is rain then minimum temperature drops or else it increases. However, specifying the range is difficult to predict.
Photograph by RamizP