IMGW warns of thunderstorms in eastern Poland on Saturday: up to 25 mm rain and 60 km/h gusts

Alert zone and timing

The Institute of Meteorology and Water Management (IMGW) has issued first-degree thunderstorm warnings for four voivodeships in north-eastern and eastern Poland. The alerts will be in force on Saturday, 11 July 2026, from noon (12:00) until 19:00 local time. The affected areas include the whole of Podlaskie voivodeship, the northern parts of Lublin voivodeship (specifically the powiats of bialski and the city of Biała Podlaska), and the eastern parts of Warmian-Masurian and Mazovian voivodeships. In Warmia-Masuria the warnings cover powiats such as szczycieński, mrągowski, kętrzyński, węgorzewski, giżycki, piski, gołdapski, olecki and ełcki. For Mazovia, the alert extends to przasnyski, makowski, ostrołęcki (including the city of Ostrołęka), ostrowski, wyszkowski, węgrowski, sokołowski, siedlecki (including Siedlce) and łosicki. This level-one alert indicates conditions favourable for hazardous weather that may cause material damage and pose a risk to health and life.

Thunderstorm and rain details

According to IMGW, thunderstorms moving across the eastern half of the country could produce moderate rainfall of 20 to 25 litres per square metre, with local totals possibly reaching 25 mm in the north-east when several storm cells accumulate over the same area. Wind gusts during the storms are forecast to reach up to 60 km/h, and small hail or ice pellets may fall locally. The institute posted on social media:

In some places they may generate rainfall of 10-15 mm, only in the north-east point totals of around 20-25 mm are possible (especially in the case of accumulation from several cells) and wind gusts of up to around 60 km/h, as well as small hail or ice pellets.

Drivers and outdoor event organisers should expect disruptions, including possible road delays and the cancellation or postponement of open-air gatherings. The weather service recommends following updates throughout the day.

Broader weather picture for Saturday

Beyond the warned areas, Saturday’s weather across Poland will be changeable. Cloud cover will be moderate to heavy, with scattered showers and local thunderstorms, mainly in the eastern half of the country. Maximum temperatures will vary sharply: around 18 °C in the north-east, 22 °C in central regions, up to 25 °C in the west, and a cooler 17-19 °C in the Carpathian foothills. Winds will be light to moderate, but stronger gusts are expected along the Baltic coast; during storms, gusts nationwide may reach 60 km/h. In the mountains, particularly the Sudetes, gusts could be even higher overnight.

Sunday outlook and safety advice

The unsettled pattern will persist into Sunday, as eastern Poland remains under the influence of a low-pressure system centred over Lithuania, Latvia and Belarus, in an unstable polar air mass. Forecasters say elevated moisture levels and weak steering flow mean the main thunderstorm hazard will be heavy rainfall. Daytime highs on Sunday will range from 18 °C in the far east to around 22 °C in the centre and up to 28 °C in western regions. Winds will be moderate and gusty, gradually turning from westerly to northerly, with gusts reaching 75 km/h on the peaks of the Sudetes. Overnight from Saturday into Sunday, residual thunderstorms may still produce downpours in the north-east and centre, with minimum temperatures dropping to 11-16 °C (9-11 °C in the Carpathian foothills).

Residents in the warning zones are advised to secure loose objects, avoid sheltering under trees during storms, and monitor IMGW’s latest bulletins. The first-degree alert means that although widespread severe damage is not expected, localised flooding, hail damage and travel disruption remain possible.