The southern region of Małopolska was worst affected, with 651 incidents reported.
In Targanice, a tree brought down by strong winds fell onto a horse-drawn carriage carrying 12 passengers, injuring five, though none seriously.
Kraków's Balice airport was forced to suspend operations after 5 p.m. local time due to the severe conditions, while power cuts were reported in parts of the city.
In the neighbouring Silesia region, firefighters responded to 421 incidents, most heavily Bielsko, Cieszyn and Żywiec.
Crews spent much of Sunday clearing fallen trees, unblocking culverts and pumping water from flooded basements.
On Żywiec Lake, a sudden squall capsized two cabin yachts.
One was pushed ashore by the waves and later righted by rescue teams; the other, described as large and heavy, flipped upside down mid-lake despite the crew's attempts to lower its sails in time.
In Bielsko-Biała, a tree fell onto a passing bus, while another crushed a car travelling towards Szczyrk.
No injuries were reported in either incident.
Heavy rain also battered the eastern Lublin region, where firefighters answered nearly 200 calls, mostly for flooded basements.
The city of Biała Podlaska saw a downpour so intense it flooded a roundabout near the city centre.
(ał)
Source: polskieradio24.pl