Experts Explain

Fact Check: Why the Heat Isn’t a “Measurement Lie”

Six days with temperatures of 40 degrees and higher—the extreme summer of 2026(Bild: Krone-Collage/APA/ZOE-SOPHIE ZIMMERMANN, Elena Überbacher)

Incorrectly measured, manipulated “from above,” fabricated to distract from other issues. The second nationwide heat wave has set new, disheartening records in eastern Austria. A high of 41.2 degrees was recorded on Wednesday in Bad Deutsch-Altenburg. It’s never been this hot in the country before. While everyone is probably sweating under the current conditions, not everyone is quite willing to believe the temperatures are real. So we asked: How are these readings actually taken?

Hot? Yes! But is it really that hot? Especially on social media these days—not least in the comments under posts by weather services—there’s a growing number of users expressing doubts about measurement methods, temperature readings, and even the number of heat-related deaths this past June.

In some cases, this goes beyond personal perceptions along the lines of “It used to be hot back then” or “Yeah, it’s just summer.” Now, the measurements themselves are being called into question, and reputable weather services are being accused of deliberately playing on people’s fears. 

FPÖ rails against “heat panic”
The issue of heat has recently resurfaced on the political stage. The FPÖ is stirring up sentiment—a highly debatable move—and railing against the alleged “heat panic.” Under the headline “Heat Panic as a Distraction from the Vaccine Disaster of the Establishment Parties,” the current heat wave and its fatalities were linked to alleged vaccine-related deaths.

Although the post in question has since been deleted, “Die Tagespresse” recently responded to it, succinctly stating: “For the first time: Tagespresse at a loss.” The article can still be found on the party’s website, albeit under a different title.

Criticism rained down from the SPÖ: On Thursday, SPÖ parliamentary group leader Philip Kucher railed, “The FPÖ believes the thermometer is in cahoots with the system.” And: For the Blues, even “the thermometer is now too left-wing.”

Seven days with 40 degrees and higher—six of them in 2026
But even meteorologists have been staring at the weather data with disbelief over the past few days and weeks: On three separate days in each of the three summer months of 2026, a high of 40 degrees or more was recorded in Austria. And in total, there were six days this year with temperatures of 40 degrees or higher—there have been seven such days in total since the year 1767 (!). We are further away than ever from a “normal summer like back then.” And the trend toward hotter and ever-hotter weather has been noticeably evident for several years now.

The WMO

The World Meteorological Organization (WMO) guidelines establish globally recognized standards for the measurement of meteorological and environmental data.

It describes which instruments should be used, how they must be correctly installed, calibrated, and maintained, and the methods for collecting weather and climate data.

The goal is to ensure that measurements—such as those of temperature, precipitation, wind, air pressure, or humidity—are comparable and reliable worldwide. 

A semi-automatic weather station in Mittersill (Salzburg)(Bild: GeoSphere Austria)

But how are these measurements actually taken? The measuring stations across the country are part of the official Austrian monitoring network, operated by GeoSphere Austria. Their locations are not chosen arbitrarily but must instead comply with strict international standards and regulations. The WMO guidelines are decisive.  

Was es für genaue Daten braucht

Messstationen: Das sind die Kriterien

Wettermessungen sind weit aufwendiger, als man vielleicht meinen mag. Denn es reicht nicht einfach nur, an einem beliebigen Ort eine Station zu errichten. Denn: Wetterdaten können natürlich nur verglichen werden, wenn alle nach denselben „Regeln“ spielen und messen.

• Die Temperatur wird im Schatten gemessen. Thermometer dürfen nicht in der Sonne hängen, sondern befinden sich in einer speziellen weißen Wetterhütte oder einem Strahlungsschutz, damit die Sonne das Messergebnis nicht verfälscht. Genau vorgeschrieben ist auch, wie hoch ein Thermometer angebracht werden muss – nämlich etwa 1,25 bis 2 Meter über dem Boden. 
• Der Standort ist entscheidend. Es braucht „ebenes, mit kurzem Gras bewachsenes Gelände, keine künstlichen Wärmequellen in der Nähe, freie Anströmung ohne Hindernisse, ausreichender Abstand zu Bebauung und versiegelten Flächen“, erklärt Ubimet-Meteorologe Peter Wölflingseder. Gerade Letzteres hätte erheblichen Einfluss auf die Messungen. „Versiegelte Flächen heizen sich tagsüber stärker auf und speichern Wärme, die nachts wieder abgestrahlt wird – das kann lokal mehrere Grad ausmachen. Genau deshalb ist die Standortwahl einer der wichtigsten Qualitätsfaktoren für offizielle Messungen“, so der Meteorologe.

• Dass es jedoch auch in jeder österreichischen Landeshauptstadt eine Messstation mitten in der Stadt gibt (Stichwort Bebauung und Versiegelung), erklärt Wölflingseder so: „Es gibt in jeder Landeshauptstadt zumindest eine Station mitten in der Stadt, aber auch weiter außerhalb am Randgebiet, z. B. Linz und Linzer Flughafen, Salzburg und Salzburger Flughafen. Nicht jede Station in einer Innenstadt erfüllt dabei immer die Qualitätskriterien, aber trotzdem bilden sie ab, wo viele wohnen, deshalb haben sie eine Berechtigung.“

• Die Standorte werden auch regelmäßigen Kontrollen unterzogen, erklärt Klimaforscher Marc Olefs von GeoSphere Austria gegenüber der „Krone“: „Bei relevanten Veränderungen wird die Situation bewertet und falls nötig ein besser geeigneter Standort gesucht. Verlegungen werden dokumentiert, damit sie bei späteren Auswertungen berücksichtigt werden können.“ Auch werden die Sensoren in regelmäßigen Abständen gewartet, in der Regel alle zwei Jahre. „Dabei werden Messgeräte, Datenübertragung und Standort kontrolliert. Sensoren werden nach fachlichen Vorgaben kalibriert oder bei Bedarf ausgetauscht.“
• Sogenannte Plausibilitätskontrollen stellen sicher, dass ungewünschte Einflüsse auf die Messwerte von Messstationen im Ernstfall erkannt werden. Dabei werden benachbarte Stationen verglichen oder es fällt beim Stationsservice auf, erklärt der Klimaforscher.

Private weather stations are less accurate
It is emphasized that readings from private and professional weather stations are in any case not comparable, and there can certainly be significant differences in the values. This is due in no small part to inexpensive sensors or unfavorable placement that simply does not meet WMO criteria. “Individual app or balcony readings are interesting, but not directly comparable,” says meteorologist Peter Wölflingseder (Ubimet).

If temperatures rise over decades and certain extremes increase, this is a clear sign of climate change.

Klimaforscher Marc Olefs von GeoSphere Austria

“An individual extreme value has only limited significance”
“Individual locations and records can certainly be discussed from a technical perspective,” says climate researcher Marc Olefs of GeoSphere Austria. “However, when assessing climate trends, what matters most are long-term measurement series and the combined data from many stations.” He continues: “A single extreme value has only limited significance. However, if—as in the current case—new records are measured at more than one-third of the stations, this indicates an extraordinary, large-scale event.”

Global warming is also evident independently of weather stations, for example through glacier retreat, fewer days with snow cover, and earlier flowering times. “It therefore cannot be explained by individual unsuitable locations (of measuring stations, note).

Olefs noted: “A single extreme event is, first and foremost, weather. What matters for climate change is the long-term trend: If temperatures rise over decades and certain extremes increase, that is a clear signal of climate change.”