Study: 40°C heat extremes now plausible in Nordic countries
Researchers find a six-fold increase in probability of extreme heat reaching Norway, Sweden, and Finland since 1981.
What to know
- A peer-reviewed study in Nature finds that 40°C heat extremes, once considered implausible, should no longer be discounted in Norway, Sweden, and Finland.
- The annual probability of reaching 40°C in the Nordic region has increased six-fold since 1981 to 0.53% in 2025; Norway faces a 10.9% annual risk of breaking its national heat record.
- The research attributes this shift to climate change and the combination of strong atmospheric blocking patterns with low soil moisture, and recommends Nordic countries prepare infrastructure and populations for substantially higher temperatures.
Rantanen et al. Researchers
How it unfolded 2 developments, newest first · click a bar or a number to jump posts
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Study quantifies country-specific heat record risks
The paper estimates that under present-day climate conditions, Norway has the highest annual probability of exceeding its observed national heat record at 10.9%. It also provides a specific probability estimate for 2025: 0.53% annual probability of reaching 40°C somewhere in the Nordic region (95% confidence interval: 0.38–0.70%).
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background
Study identifies mechanism for Nordic extreme heat — The research attributes extreme heat events in the Nordic region to the joint occurrence of strong omega blocking (a persistent atmospheric pattern) combined with low soil moisture conditions in northern Europe. The study emphasizes that Nordic infrastructure and populations are generally less adapted to extreme heat than warmer climate regions.
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2
Nature publishes study on Nordic extreme heat risk
Peer-reviewed research from Rantanen and colleagues, published in Nature, shows that 40°C temperatures are no longer implausible in Norway, Sweden, and Finland. The study analyzed seasonal weather forecasts covering 7,308 years of simulated summers and found a six-fold increase in the annual probability of reaching 40°C in the Nordic region since 1981.
“40 °C cannot be considered implausible in the Nordic countries.”
— Rantanen et al. -
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New paper! Do you remember the heatwaves in Europe this summer, when temperatures reached close to 40 °C even on the Baltic coast? Our new paper shows that 40 °C extremes should not be considered implausible in the Nordic countries of Sweden, Norway and Finland.
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