IMGW issues thunderstorm warnings across eastern Poland ahead of Corpus Christi long weekend

Tuesday's warnings

Poland's Institute of Meteorology and Water Management (IMGW) has issued first-degree thunderstorm warnings for Tuesday, 2 June, covering the voivodeships of Podlaskie, Lubelskie, Mazowieckie (excluding north-western counties), Warmińsko-Mazurskie (eastern counties), Świętokrzyskie (eastern counties), and Podkarpackie. The warnings will be in force from 11:00 to 20:00.

In these regions, forecasters expect storms accompanied locally by heavy rainfall of 20 to 30 litres per square metre, locally around 35 l/m², and wind gusts up to 55 km/h. Hail may fall locally. IMGW describes a first-degree warning as indicating conditions conducive to dangerous meteorological phenomena that may cause material losses and pose a threat to health and life.

The greatest threat in storm areas will be heavy, at times torrential, rainfall.

A divided country on Tuesday

While the east braces for storms, western Poland will see a markedly different picture. Temperatures in the west are forecast to reach 25–27°C under sunny skies, as warmer and drier air flows in. In central and eastern regions, thermometers will show 21–23°C, with intermittent showers and thunderstorms still possible. The country remains under the influence of low-pressure systems connected to areas over the North Sea and the Baltic, with warmer polar maritime air moving in.

Wednesday's outlook

On Wednesday, the storm zone shifts westward. IMGW's threat forecast indicates that first-degree thunderstorm warnings may be issued for the voivodeships of Zachodniopomorskie, Lubuskie, Dolnośląskie, Wielkopolskie, Opolskie, Śląskie, Małopolskie (western counties), Świętokrzyskie (western counties), and Łódzkie (excluding the north). In Lubelskie, Mazowieckie (excluding northern counties), and northern Łódzkie, warnings for heavy rain with thunderstorms may apply instead. During storms, rainfall totals could reach 30 mm and wind gusts up to 75 km/h.

Corpus Christi and the long weekend

Thursday, 4 June — the Corpus Christi public holiday — is expected to bring the most demanding weather of the period. First-degree thunderstorm warnings may appear in Mazowieckie, Lubelskie, Podkarpackie, Małopolskie (excluding western counties), and Świętokrzyskie (excluding the west). Forecasters warn that locally intense rainfall, hail, and wind gusts of around 60 km/h could develop, posing a risk to outdoor Corpus Christi processions.

More and more indications suggest that this year's Corpus Christi may be marked by very dynamic weather.

Temperatures on Thursday will remain high, ranging from 22 to 26°C in the west and centre, while the Carpathian foothills will stay cooler at no more than 16°C.

Friday through Sunday

The most active atmospheric situation may unfold between Friday and Monday. On Friday, storms are most likely in the north and east, with the precipitation and lightning zone potentially shifting towards central and southern Poland in subsequent hours. IMGW may issue yellow thunderstorm warnings for Lubelskie, Małopolskie, and Pomorskie, while Warmińsko-Mazurskie could see first-degree warnings for heavy rain with storms.

Saturday looks even more unsettled, with forecasts suggesting nearly the entire country will be within range of thunderstorms — the only possible exception being north-western areas. A cold front moving in from the west will begin pushing out the warm air mass, bringing cooler conditions under cloudy skies. By Sunday, rainfall should be limited to the north, and warmer air from southern Europe is expected to return from midday.

What the warnings mean

IMGW's first-degree warning — the lowest in a three-tier, ascending scale — signals conditions favourable for hazardous meteorological phenomena. The institute advises caution, recommends following weather updates, and warns of possible disruptions to road traffic, outdoor events, and processions. The threat forecast itself is described as an indicative weather outlook serving to provide early public information about the possibility of dangerous phenomena occurring.