Heatwave in Central Europe: Temperatures up to 40 degrees in Austria and thunderstorms with hurricane-force gusts expected in Germany

GeoSphere Austria forecast on Wednesday in a press release that the heat will continue to build day by day across the entire federal territory and will reach its peak on Friday. Meteorologist Thomas Turecek explained: "Heiß werde es demnach zwar im gesamten Bundesgebiet, besonders heiß jedoch erneut im Osten." Particularly affected, according to GeoSphere Austria, are once again the eastern lowlands, Vienna, Lower Austria, and Burgenland.

For eastern Austria, 38 to 39 degrees are expected, with isolated spots possibly reaching 40 degrees. Turecek verbatim: "Einzelne Stationen im östlichen Flachland können 38 bis 39 Grad erreichen. Vielleicht sogar 40, ähnlich wie im Juni." This puts the forecast at the level of the June heat, when on 28 June the Vienna-Innere Stadt measuring station recorded 40.0 degrees – the highest value ever measured in the federal capital. The following day, Bad Deutsch-Altenburg reached 40.1 degrees.

Why no red heat warning

The record of 40.5 degrees from August 2013, however, still stands. During the night of 29 June, the air temperature at Vienna's Jubiläumswarte did not drop below 27.3 degrees – the warmest minimum value ever recorded at a GeoSphere Austria station. Meteorologists refer to such nights as tropical nights.

A red heat warning, the highest level, will nevertheless not be issued. According to GeoSphere Austria, this is justified by two factors: First, on Saturday a weak disturbance will cause the values to ease to 34 to 35 degrees. "Es ist also lediglich an einem Tag extrem heiß", said Turecek. Second, the early morning temperatures of 14 to 22 degrees are relatively moderate. With the exception of densely built-up urban areas, nighttime cooling is therefore sufficient.

Third wave of the summer

The current weather situation already marks the third heatwave of the year for western and southern Austria. The first wave began on 24 May and lasted five to nine days. The second wave began in mid-June, covered all of Austria, and persisted in some lowland regions for 18 to 35 days – according to GeoSphere Austria, a particularly extraordinary duration. At individual measuring stations, including Bregenz and Eisenstadt, the second wave is still considered not fully ended according to the Kyselý definition, because temperatures in the meantime never dropped sufficiently.

According to the Kyselý definition, a heatwave continues as long as daily maximum values do not fall below 25 degrees and their mean value does not drop below 30 degrees. "An einzelnen Messstationen gilt sie nach wissenschaftlicher Definition sogar bis heute als nicht vollständig beendet, weil die Temperaturen zwischenzeitlich nie ausreichend zurückgingen", the GeoSphere Austria analysis states. For Sunday and Monday, temperatures of around or above 35 degrees are again forecast regionally; a massive change in weather is not in sight, according to Turecek: "Es ist keine massive Wetterumstellung in Sicht. Was im Moment fehlt, ist ein eindeutiger Temperaturrückgang um zehn bis 15 Grad."

Drought and its consequences

The ongoing drought is worsening the situation. Climatologist Alexander Orlik explained: "Damit war es in Österreich – zumindest seit dem Beginn des 20. Jahrhunderts – in den ersten sieben Monaten eines Jahres nicht mehr so niederschlagsarm." The precipitation-poor conditions prevailing since December 2025 have also changed little in July. By the end of July, there is a nationwide average shortfall of around 30 percent compared to a normal precipitation year: instead of the climatologically usual 609 millimetres, only 426 millimetres were measured by 27 July – a deficit of about 30 percent. Comparable deficits last occurred in 1971 with minus 27 percent and in 2003 with minus 25 percent.

The drought is already having measurable consequences. In Styria, some hydroelectric power plants had to be shut down because of the lack of water. The University of Natural Resources and Life Sciences, Vienna, recorded 269 forest fires since the beginning of the year, up from 196 for the entire previous year. 83 percent of forest fires in Austria are statistically attributable to human behaviour. New monthly records were set at 157 of 277 Austrian weather stations in June, exceeded on average by 1.4 degrees.

The German Weather Service (DWD) is also expecting an escalation in Germany. "Mit stellenweise fast 40 Grad steht Deutschland am Donnerstag der heißeste Tag der aktuellen Hitzewelle bevor", the DWD stated in Offenbach. Temperatures will rise to 26 to 31 degrees at the coast, otherwise to 32 to 39 degrees. On Wednesday, widespread strong, in some areas extremely strong, heat stress already had to be expected in the southwest, west, and northwest.

Heat and thunderstorms in Germany

MDR meteorologist Michaela Koschak warned that the heat affects all of Germany and that tropical nights are once again an issue in inner cities. On Wednesday morning at 6 a.m., temperatures in central Germany were between 12 and 15 degrees, already at 20 degrees in densely built-up areas, and likewise at 20 degrees in the Harz mountains. During the course of the day, up to 34 degrees were expected in central Germany, locally even more in the Jena area. Koschak said: "Also wir müssen uns auf heiße Tage einstellen. Aber auch wir werden ordentlich ins Schwitzen kommen."

In addition to the heat, there is a risk of storm or even hurricane-force gusts in parts of Germany. DWD meteorologist Nico Bauer explained: "Bei diesen Windgeschwindigkeiten können Bäume entwurzelt werden und größere Gegenstände umherfliegen." Especially in the north, thunderstorms on Thursday can be severe, bringing heavy storm gusts and in isolated cases even hurricane-force gusts. "Dabei gilt bei Aufenthalt im Freien Obacht", warned Bauer.

On Thursday, the DWD expects a sunny day in the southeast, but showers and isolated thunderstorms will form from the southwest and west, spreading to the central regions and the north by evening. During the night into Friday, showers and thunderstorms will move on to the northeast; by morning, new ones may develop in the southwest. "Kühler, aber stellenweise mit Gewittern beginnt das Wochenende", the DWD announced. On Friday, there will be in some cases heavy showers and thunderstorms from the southwest across the central regions to the northeast, with a local risk of severe weather. Temperatures on Friday are expected to range between 23 and 36 degrees.

Climatological trend

For Friday, the DWD also announced very hot summer weather in the southeastern half. Bauer: "Während es in der Südosthälfte erneut hochsommerlich heiß wird, liegen die Temperaturen am Nachmittag von der Ostsee bis an den Niederrhein lediglich noch bei angenehmen 24 bis 28 Grad." The midsummer weather is therefore not coming to an end for the time being, as Bauer stated verbatim: "Der Hochsommer scheint sich also noch nicht geschlagen zu geben."

The DWD recommends avoiding the heat where possible, drinking sufficient water, and keeping indoor spaces cool. With the cooler temperatures on the night into Friday, one can ventilate better than in the previous nights. On Sunday and at the beginning of the coming week, the heat is expected to return, especially in the south and southeast.

Climatologists see a clear long-term trend in the frequency and intensity of heatwaves. "Während es früher meist nur ein bis zwei Hitzewellen pro Jahr gab, treten inzwischen regelmäßig zwei bis drei auf. Gleichzeitig dauern sie länger und erreichen deutlich höhere Temperaturen als noch vor wenigen Jahrzehnten", an analysis states. The absolute maximum air temperatures in a heatwave have accordingly risen by about three degrees from the 1980s to the 2020s.

Health consequences and outlook

A severity index combining the duration and average peak temperature of heatwaves rose between the climate around 1975 and today's climate at nine provincial main stations from 5.3 to 12.9 degree-days – a factor of 2.4. The earliest start of a heatwave has also shifted earlier: in the reference period 1961 to 1990 it was 1 June, and in the period 1991 to 2020 it was already 29 April. "Hitzewellen treten heute nicht nur häufiger auf, sie dauern vielfach länger und