Poland sweats as IMGW warns of 38°C heatwave, violent storms and tropical nights

IMGW issues top-level heat alerts

Poland's meteorological institute IMGW issued third-degree heat warnings on Sunday for districts in the Lublin, Subcarpathian, and Lesser Poland provinces. Daytime highs of 30 to 37°C are forecast, with overnight lows of 18 to 23°C. The warnings remain in place until 20:00 on Wednesday. Second-degree heat warnings cover parts of Silesia, Lesser Poland, and Subcarpathia, where temperatures will reach 30 to 34°C. A first-degree thunderstorm warning is also in effect for the Tatra county on Sunday afternoon, bringing heavy rain of 20-25 l/m², hail, and wind gusts up to 70 km/h.

Brief cooling on Sunday before the next wave

Sunday offers a temporary respite across much of the country. Northern and western areas will see sunny skies, while the south and east experience variable cloud and isolated showers. Thunderstorms are forecast in the Carpathians and Podkarpacie, with rainfall totals of 10 to 20 mm and gusts of 60 km/h. Maximum temperatures will range from 20°C on the Baltic coast to 30°C in the southeast. Overnight from Sunday to Monday, skies will clear except in the south, where local storms may persist in the Tatras, Bieszczady, and Sudetes. Lows will drop to 11°C in the north, 14-16°C in the centre, and 19°C in the southeast.

Heat spike: Monday to Wednesday

Tropical air from Africa and the Azores will push temperatures sharply higher from Monday. That day will be predominantly sunny, but afternoon storms with hail will erupt in the south and centre; maximum temperatures will reach 32 to 34°C in the south. The heat intensifies further on Tuesday and Wednesday. On Tuesday, southern and central regions will bake in 35 to 38°C, while a belt of storms with large hail stretches from Dolny Śląsk to Podlasie. Wednesday will be the hottest day, with 36 to 38°C again in the south and centre, and only the far south and east escaping widespread thunderstorms. Winds will be light to moderate, shifting from easterly to southerly, then westerly by Thursday.

Storms and the threat of hail

Instability will be driven by a low-pressure area over Poland, which is expected to generate towering thunderstorm clouds. Many storms will be accompanied by torrential downpours, some delivering 20-30 mm in short periods, and large hail. Wind gusts in the most vigorous cells could exceed 70 km/h. The volatile pattern is set to last through at least Thursday, when the northwest will finally cool but southeastern districts will still record 34 to 36°C with scattered storms.

Tropical nights and health advice

IMGW synoptyk Michał Ogrodnik highlighted the danger of warm nights, which the institute defines as those when the temperature stays at or above 18°C.

When the night-time minimum temperature does not fall below 18°C, we can speak of a tropical night. Residents of Mazowsze, Subcarpathia and Lesser Poland will feel it.

The night of Saturday to Sunday already brought tropical conditions to those three voivodships, with lows of 18 to 20°C in the southeast and 18°C in Warsaw. Similar nights are expected to recur during the heatwave, making it harder for the body to recover. IMGW advises the highest level of caution, urging residents to follow updates and prepare for significant disruptions to daily life.