For every degree Celsius above 30 degrees, the trains arrived at the stations on average 20 seconds later.Image: www.imago-images.de
At temperatures above 30 degrees Celsius, rails expand, overhead lines sag and the train slows down. In May and June alone, this added up to 1,397 additional days of delays across Europe and thousands of trains were canceled. These regions were affected the most.
Jul 16, 2026, 4:47 amJul 16, 2026, 4:47 am
The heat wave is pushing the European rail network to its limits. At the beginning of summer, rail traffic was delayed by an additional 1,397 days due to the hot temperatures – plus 20,000 trains were canceled. Between May 1st and July 5th investigated the Belgian startup chuuchuu BV Train delays in Austria, Belgium, France, Germany, Hungary, Italy, the Netherlands and Switzerland.
The conclusion of the study: The railway doesn’t like the heat. As soon as temperatures exceed 30 degrees Celsius, the rails expand. At extreme temperatures, sudden distortions can occur. This means that the rail moves sideways by more than 50 millimeters.
With the heat, overhead cables are also more likely to sag. Speed limits also apply. The result: longer delays and more train cancellations across Europe.
In fact, European trains were delayed by an average of 1.7 minutes more (from 4.2 to 5.9 minutes) when the temperature exceeded 30 degrees. In addition, trains were 1.5 percentage points earlier (from 2.5 to 4 percent).
The higher the temperature, the longer the delay
For every degree Celsius above 30 degrees, trains were delayed by an additional 20 seconds on average. The relationship between heat and delays can be easily explained, especially in France and Hungary. The trend line explains 58 percent of the fluctuations in train delays through the maximum temperature. The graph, which takes the average of all countries into account, is even more robust at 63.8 percent.
Note on the graphics: The distances on the x and y axes change with the countries. A purely visual comparison of the slope of the trend line should be treated with caution.
These countries felt the heat the most
The heat did not have the same impact everywhere. The map shows stations in Europe. The color indicates by what percentage the delay increased on days with temperatures above 30 degrees Celsius.
The countries were not equally affected by the heat either: Italy’s average delay only increased by 12 percent at temperatures above 30 degrees. France’s average delay increased by 70 percent during heatwaves. But: Italy already had quite long delays on average (5.6 minutes) without heat waves – they just didn’t get much longer when it got hot.
In Switzerland, for example, the relative delay increased by 25 percent when temperatures exceeded 30 degrees – but in absolute terms this was only half a minute because the average delays in Switzerland were generally very short.
As summer temperatures rise, this pattern is likely to strengthen rather than weaken in the future. So the rails are melting more often and sooner.
For travelers this means: Anyone traveling by train through Europe in midsummer should prepare for more delays, not just more hot days.
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