Heat wave—yes or no?

The Dog Days Are Coming: Here’s What the Forecasts Say

Is the next major heatwave on the way?(Bild: APA/HANS KLAUS TECHT)

The dog days are approaching—and with them, the hottest period and most stable weather conditions of the summer are expected. That basically means: hot weeks in Austria. But is that really true? Is it even possible to make reliable forecasts at this point? We investigated.

There’s already a lot of talk about an impending heat dome that could soon spread to Central Europe—and is expected to herald the next massive heat wave. But can we say that for sure just yet? 

Especially in southern Spain, maximum temperatures of over 40 degrees are expected again, and around 35 degrees in southern France.

Meteorologe Peter Wölflingseder

“The only region where the situation is more concrete at the moment is southwestern Europe: A strong high-pressure system is building over the Iberian Peninsula, bringing subtropical air from Africa,” explains meteorologist Peter Wölflingseder.

Temperatures are likely to rise sharply again, particularly in southern Spain—“highs of over 40 degrees” are expected—and around 35 degrees in southern France, according to the weather expert. However, the heat wave apparently isn’t here to stay. “As things stand now, this high-pressure system will be displaced by a low-pressure system as early as this weekend, and temperatures there will then drop again.”

Do the “dog days” come from dogs?

• Let’s get this out of the way right away: no. The “dog days” (July 23 to August 23) have nothing to do with the furry, four-legged animal.
• Rather, the term dates back to ancient astronomy—it refers to the star Sirius, known as the “Dog Star.”
• The name is derived from the constellation “ Canis Major” (the Big Dog )—Sirius (Alpha Canis Majoris) is its brightest star. In ancient Egypt and ancient Rome, the time when Sirius became visible in the morning sky coincided exactly with the extreme summer heat. 
• However, the appearance of Sirius in the sky hassinceshifted significantly later. Today, due to the shift in the Earth’s axis, it actually heralds the beginning of early fall in Central Europe.
• Many farmers’ sayings also revolve around this time of year. One well-known saying goes: “If the Dog Days are hot, winter will be long and white.” 

Summer-like warmth in the Vienna area
And how will the weather develop here in the coming days? “This week, following the passage of a front accompanied by showers and thunderstorms, a cool northwesterly flow will set in today, and temperatures will gradually drop. At times, it will even be slightly cooler than usual for this time of year in some regions,” says Wölflingseder. However, it will remain summery and warm in the Vienna area, with highs between 25 and 27 degrees.

“Uncertainty in the Models”
“Starting Friday, the uncertainty in the models increases significantly. While it appears that temperatures will gradually rise again afterward, it’s still completely unclear to what level.”

As for whether we, too, are facing a heat wave like the one in southwestern Europe, no reliable predictions can be made at this time. “The range of model outcomes is simply still too wide for that,” Wölflingseder emphasizes. However, based on the current situation—subject to the dynamic forecast conditions—a record heatwave like the one in June is unlikely.