IMGW Issues First-Degree Thunderstorm and Flood Warnings for Most of Poland on Monday
Poland's meteorological institute has issued first-degree warnings for thunderstorms, heavy rain, and potential flooding across the majority of the country's voivodeships, with the most severe conditions expected in the south.
The Institute of Meteorology and Water Management (IMGW) has issued a series of first-degree weather warnings for Monday, 1 June, covering nearly the entire territory of Poland. The alerts, which are the lowest in a three-tier scale, warn of thunderstorms, heavy rainfall, and a rapid rise in river levels.
The approaching low-pressure system
Poland is currently under the influence of a low-pressure system named Mechtylda, whose center is moving through the Czech Republic, Slovakia, and Hungary near the country's southern borders. A cold occlusion front stretching from the Norwegian Sea across the western Baltic Sea into Poland is expected to bring unsettled weather throughout the day. The front is most active in its southern part, where it will deliver the heaviest precipitation.
Thunderstorm warnings for twelve voivodeships
First-degree thunderstorm warnings will come into force at noon and remain active until 7 p.m. on Monday. They cover the entirety of the Mazowieckie, Świętokrzyskie, and Lubelskie voivodeships, as well as parts of Pomorskie, Warmińsko-Mazurskie, Podlaskie, Kujawsko-Pomorskie, Wielkopolskie, Łódzkie, Śląskie, Małopolskie, and Podkarpackie. During these storms, rainfall could reach up to 25-35 millimeters, and wind gusts may hit speeds of 60 to 85 kilometers per hour. The phenomena are expected to be short-lived, but moderate rainfall may persist after the storms pass, posing a particular risk to urban areas.
- Heavy rain warnings expire in Lubuskie and Dolnośląskie voivodeships.
- Thunderstorm warnings come into force across 12 voivodeships.
- Heavy rain warnings expire in Opolskie, Śląskie, and Małopolskie voivodeships.
- Thunderstorm warnings expire; hydrological warnings remain into the evening.
Heavy rain and flood alerts in the south
Separate first-degree warnings for heavy rain accompanied by thunderstorms are in effect for parts of the Dolnośląskie, Opolskie, Śląskie, and Małopolskie voivodeships. In these regions, moderate to heavy rainfall is forecast, with totals potentially reaching 25 to 60 millimeters. These alerts will expire at 10 a.m. in Lubuskie and Dolnośląskie, and at 3 p.m. in Opolskie, Śląskie, and Małopolskie.
Additionally, first-degree hydrological warnings have been issued for parts of the Lubuskie, Dolnośląskie, Opolskie, Śląskie, and Małopolskie voivodeships. These indicate a risk of a sudden rise in water levels, which could locally and briefly reach or exceed warning stages, especially during intense rainfall and thunderstorms.
Regional impact and expected conditions
In the morning, heavy cloud cover and rainfall were already observed over the Śląskie, Małopolskie, and Podkarpackie voivodeships. Throughout the day, the rain zone will persist over the south, with particularly intense precipitation in the southeast. The most dynamic weather, including thunderstorms with hail and strong wind gusts of 65-70 km/h, is forecast for a belt stretching from Mazowsze through Warmia to Podlasie. Only the far northeastern and northwestern fringes of Poland are expected to remain dry. Despite the unsettled conditions, temperatures will remain relatively mild, ranging from 20 to 23 degrees Celsius across most of the country.
Official warnings and safety advice
A first-degree IMGW warning indicates conditions conducive to dangerous meteorological phenomena that may cause material losses and pose a threat to health and life. The institute advises caution, particularly recommending that people avoid open spaces during storms and stay updated with the latest weather communications. Outdoor events may face disruptions or cancellations, and traffic delays are possible due to the hazardous conditions.


