Heat across five editions of an ultracycling race

Which edition of the Madrid-Barcelona by Pedalma was the hottest, and where on the route does the heat hit? A comparison built from my own GPS files.

I have ridden the Madrid-Barcelona by Pedalma, a non-stop ultracycling race that lasts more than a day, in 2021, 2023, 2024, 2025 and 2026. My bike computer recorded the temperature in all five editions with the same device, so the readings can be compared with each other. I used them to answer two questions: which edition was the hottest, and where on the route is the heat concentrated?

What I found

Edition	Mean temperature	Hours above 30 °C
2026	29 °C	about 16
2025	26 °C	about 10
2021	22 °C	about 8
2024	20 °C	about 2
2023	17 °C	about 2

• 2026 was the hottest of the five editions, with the highest mean temperature and the most hours of intense heat. Its curve sits above the others at almost every hour of the day, nights included.
• Where the heat hits depends on the start time. With an evening start (around 18:00), riders cross the mountains at night and meet the heat in the second half, on the inland plain around Lleida at midday of the next day, where the peaks close to 40 °C were recorded. With a morning start (around 10:30) it is the opposite: the heat comes at the beginning, on the plateau and the first climb, at 33 to 37 °C, and the plain is crossed at night.
• Altitude by itself barely changes the temperature. What decides whether a section is ridden hot or cold is the time at which you reach it.

This is an independent analysis of my own data. The figures are approximate and the trends are consistent.

Status

The study is finished.