In the western city of Poznań, part of the roof of a sports hall collapsed. Fire crews were called in to deal with flooding in five hospitals and a cathedral in the city.
Downpours turned many Poznań streets into fast moving streams.
In other parts of the country, winds uprooted trees and disrupted power supplies.
Over 23,000 people were left without electricity, most of them in the central Mazovia region, Grzegorz Świszcz from the Government Security Centre said on Tuesday evening.
Forecasters warned that further storms were expected in the first half of the night in eastern regions.
There were no reports of serious injuries as a result of the extreme weather, which came after several days of scorching temperatures.
(pk)
Source: PAP/Polish Radio