A strong hailstorm hit the city late last night, 4 May. In the VIDEO, taken by a resident, you can see the whitewashed Navigli area.

An area of low pressure moving south from northern Europe has brought to Italy, with temperatures dropping by as much as 10 degrees.
Unexpectedly heavy showers of rain and hailstones led to commuter chaos, causing some motorists to abandon their semi-submerged cars on flooded roads.
Source: https://www.facebook.com/ItaliaLiveMeteo