Gone are the days when a good monsoon in the maximum city was a given. The city would see a consistent average of about 3,000 mm of rainfall year after year from June to September. However, that is a thing of the past.

Factors such as change in monsoon pattern, global warming, burgeoning urbanisation, rampant concretisation and felling of trees has shrunk and delayed the season the city looked forward to.

In the coming years, rainfall is expected to fall much below 3,000 mm, clouds can no longer be relied on to burst in the early part of June and city slickers will have to expect water shortage as a grim certainty.

An analysis by the Indian Meteorological Department reveals that rainy days have reduced by 30% in the city. Besides, its onset is likely to be delayed which means the city may go dry in June but could experience heavy rainfall in July and August. There could be one or two heavy spells, and the season may extend to October.

"The monsoon pattern has changed and Mumbaikars will have to adjust accordingly. By and large, this is due to global warming," said Shubhangi Bhute, a scientist at the Regional Meteorological Centre in Colaba.

The UN body, Intergovernmental Panel on Climate Change, said in its report last year that Mumbai shows "heat stresses" like other megacities, which indicates that the temperature rose by around 0.7 degrees Celsius in the last century.

Other weather experts agreed there has been a clear seasonal shift and delayed onset of the monsoon. They have also projected that there will be a change in the probability of intense rainfall.

Though the monsoons are said to have arrived in Mumbai, it's not the season Mumbaikars know: There were light showers in isolated areas for short spans; none of the darkened skies and thunder and lighting that the city dwellers love and fears in equal proportion.

Most of the city sweated under a sunny sky, as temperatures hovered at 30-33°C with high humidity. IMD projects that a change in pressure and wind speed at the surface level will draw rainfall from June 27 onwards.

The city is currently facing a rainfall deficit of 69% for the period up to June 25.

An IMD official pegged the delay in the monsoon on cyclonic storm Vayu and also on moderate to weak El Nino conditions. However, these have been countered now.

The New Normal