At least six people have been confirmed dead after strong storms hit Rio de Janeiro on Wednesday evening.

Showers and storms are a common occurrence in the city and the rest of southern Brazil in the summertime, but these storms were significantly stronger due to a favourable atmosphere conducive to strong thunderstorm development.

Just days before the strong cold front pushed through, afternoon temperatures across the area were nearing 40 degrees Celsius, adding to the unstable nature of the air.

When the thunderstorms moved through on Wednesday night, they were accompanied by heavy rain and gusty winds.

Nearly 140mm of rain fell in just four hours, surpassing the February monthly average.

The heavy rain led to several mudslides, mostly in the favelas of Vidigal and Rocinha, west of the Ipanema area.

Firefighters said two people died when the bus they were on was hit by a mudslide. A third person was killed when a wall crumbled due to the downpour. Two other people were killed when their home collapsed.

Favelas have been part of Rio de Janeiro’s hillside landscape dating back to the late 1890s. Many parts of the favelas have been built without city permits and do not receive consistent city services. As a result, they lack proper drainage and the sanitation systems cannot handle such downpours.

Along with the heavy rains, strong winds gusting to over 105 kilometres per hour brought down many trees and caused widespread power outages across Rio.

The city has now begun the long and difficult process of cleaning up the mud from homes, businesses and streets.

Over the next few days, most of the active showers will be to the north of Rio de Janeiro, but a few light showers may occur in the city.