It’s not even mid-May and parts of Austria have already seen the thermometer rise to almost 30C.
After last year’s record-breaking heat, many wonder, will 2025 be even hotter?
Here’s what we know so far—and what we don’t—about how this summer could shape up.
We’re already warmer than average
April temperatures in Austria were 3.2C above the historical average between 1961 and 1990, and 1.8C warmer than the 1991–2020 reference period. Rainfall was also lower than usual, down by 24 percent. These findings come from climate monitoring by Geosphere Austria, the country’s central weather and climate institute.
Plants are blooming faster, too: current growth is about one week ahead of what used to be typical for spring, and two weeks earlier than in the 1960s. This kind of shift is one of many signs that climate change is increasingly visible in daily life.
READ ALSO: Five Austrian destinations you can reach by train to escape the heat
Another warm summer is likely
According to meteorologist Gerhard Hohenwarter from Geosphere Austria, the odds are very high that summer 2025 will once again be “too warm.”
As he told Der Standard, anything else would be surprising: Austria hasn’t had a cooler-than-average summer in over 25 years.
In Vienna, average summer temperatures have jumped from 19.2C (1971–2000) to around 22C over the past decade. Last summer was the hottest in Vienna since records began in 1775, with an average temperature of 23.1C. Whether that specific record will fall this year is uncertain, but Hohenwarter says it’s reasonable to expect a summer that’s at least one to two degrees warmer than the long-term average.
What do seasonal forecasts say?
Seasonal forecasts aren’t the same as daily weather predictions. Instead of focusing on what the weather will be like on a given day, they look at large-scale patterns in atmospheric circulation, like jet streams and ocean temperatures, to make broader projections over weeks or months.
Models from the European Centre for Medium-Range Weather Forecasts (ECMWF) suggest that July 2025 will likely be warmer than the 1993–2016 average across much of Europe, including Austria. These forecasts show a temperature anomaly of one to two degrees above normal.
READ ALSO: 8 cool places to work in Vienna on hot summer days
Still, Hohenwarter cautions that long-term forecasts become trickier in mountainous areas like Austria. While the models work well at a continental scale, local conditions—especially around the Alps—introduce much more variability.
Rain remains unpredictable
Rainfall is much harder to forecast than temperature. Even a small shift in the position of the jet stream can drastically change whether a region experiences prolonged sunshine or recurring thunderstorms.
As things stand, models predict that June could bring more rain to the northern Alps, especially between Vorarlberg and Salzburg. This would be good news for soil moisture heading into the hotter months, potentially reducing drought risk. July and August, on the other hand, are expected to bring average or below-average rainfall.
But recent forecasts have often missed the mark: Austria stayed much drier than expected for months.
READ ALSO: Vienna’s free ‘cooling centre’ lets you avoid Austria's stifling heat
Expect hot days and tropical nights
Whether or not this summer breaks records, the number of hot days (over 30C) and tropical nights (where temperatures stay above 20C) is almost certain to rise. In 2024, Vienna’s Inner City saw 52 hot days, Eisenstadt 48, and even more temperate areas like St. Pölten logged over 40.
Nights that stay uncomfortably warm are becoming a new feature of summer life across Austria, particularly in urban areas.
These kinds of temperatures can have real effects on health, infrastructure, and daily life. Cities like Vienna are continuing to expand cooling zones and shade infrastructure, but persistent heat will remain a challenge.
But don’t expect certainty
Despite better models and faster computing, reliable weather forecasts still only extend about 10 days ahead. For seasonal outlooks, Hohenwarter says we should expect general trends—not precise details. “We are in such a sensitive region in terms of weather that weather forecasts are already a major challenge—let alone a seasonal forecast,” he told Der Standard.
Comments