July 14, 2023

Climate Shift Index alert: Europe, July 2023

Analysis: Upcoming extreme heat wave in Europe linked to climate change

Climate Central analysis shows that human-caused climate change is making daily maximum temperatures for the upcoming heat wave in Italy, Germany, France, Spain and Poland at least 3 times more likely.

Note: This is an ongoing event that may continue beyond July 17. Use the Global Climate Shift Index map to stay updated on the latest climate-related heat in your region.

Forecast

A 4-day stretch of extreme and potentially record-breaking heat is forecast across Europe from July 14-17, 2023.
The event consists of two components: 1) a wave of heat that will move across France, Central, and Eastern Europe. 2) unusually hot temperatures that will persist in Spain, Italy, and the Balkans.
In France, Central Europe and Eastern Europe from July 14-17:
- The focal point of the propagating heat will start in France and Spain on July 14, travel eastwards through Germany and Poland on July 15, settle in Eastern Germany and the Baltic States on July 16, and finally begin to disperse on July 17.
- Forecasted daily highs are between 5-10°C hotter than normal across most of Western, Central, and Eastern Europe during this time period. The most extreme temperature anomalies are expected in Germany on July 15, where daily highs will reach at least 14°C hotter than normal, surpassing 35°C in some locations.
  - Erlangen, Germany: peak anomaly of 14.2°C on July 15
  - Fürth, Germany: peak anomaly of 14.2°C on July 15
  - Nuremberg, Germany: peak anomaly of 14.2°C on July 15
  - Würzburg, Germany: peak anomaly of 14.5°C on July 15
In Spain, Italy, and the Balkans from July 14-17:
- The most extreme temperature anomalies are forecast to occur on July 17, when daily highs in these regions will reach 5-10°C hotter than the average, potentially crossing the 40°C threshold in many locations across the region

Attribution Science

An analysis of the Climate Shift Index (CSI) for July 14-17 shows that climate change increased the likelihood of this event.
In France, Central Europe and Eastern Europe from July 14-17:
- Daily maximum temperatures are expected to reach CSI levels of 3-4 during each location’s maximum high heat day.
- A CSI level 4 indicates that human-caused climate change made this excessive heat at least 4 times more likely, signifying that these conditions would be extremely unlikely without climate change.
- Statistics for capital cities during the event (statistics for 500 cities available here):
  - Paris, France: peak anomaly of 7.4°C on July 14, CSI = 3
  - Luxembourg, Luxembourg: peak anomaly of 8.1°C on July 14, CSI = 2
  - Bern, Switzerland: peak anomaly of 8.8°C on July 15, CSI = 3
  - Vienna, Austria: peak anomaly of 8.0°C on July 15, CSI = 2
  - Prague, Czechia: peak anomaly of 11.3°C on July 15, CSI = 4
  - Berlin, Germany: peak anomaly of 11.0°C on July 15, CSI = 3
  - Riga, Latvia: peak anomaly of 7.4°C on July 16, CSI = 4
  - Warsaw, Poland: peak anomaly of 11.4°C on July 16, CSI = 4
  - Budapest, Hungary: peak anomaly of 7.1°C on July 17, CSI = 3
  - Kyiv, Ukraine: peak anomaly of 5.2°C on July 17, CSI = 2
In Spain, Italy, and the Balkans from July 14-17:
- Daily maximum temperatures are expected to reach CSI levels of 5 (the highest possible value) in Spain, Italy and the Balkans during the 4-day period, indicating that human-caused climate change made this heat at least 5 times more likely, which signifies an exceptional climate change event.
  - Athens, Greece: peak anomaly of 7.2°C on July 14, CSI = 5
  - Tunis, Tunisia: peak anomaly of 12.4°C on July 15, CSI = 5
  - Zagreb, Croatia: peak anomaly of 7.2°C on July 16, CSI = 5
  - Belgrade, Serbia: peak anomaly of 8.5°C on July 17, CSI = 4
  - Madrid, Spain: peak anomaly of 6.2°C on July 17, CSI = 5
  - Rome, Italy: peak anomaly of 9.9°C on July 17, CSI = 5
  - Sarajevo, Bosnia And Herzegovina: peak anomaly of 9.6°C on July 17, CSI = 5
  - Algiers, Algeria: peak anomaly of 6.6°C on July 17, CSI = 5

Quotes

Dr. Andrew Pershing, VP of Science at Climate Central, said:

“This weekend, much of Europe is going to experience unusually warm conditions. By burning coal, oil, and natural gas, humans made these conditions much more likely.”

Friederike Otto, Senior Lecturer in Climate Science at the Grantham Institute for Climate Change and the Environment, and co-lead of World Weather Attribution said:

"Europe’s current heatwave has been made hotter by climate change that is the result of human activities like burning coal and other fossil fuels. This is now the case for every heatwave, everywhere in the world. Until net greenhouse gas emissions end, heatwaves in Europe and elsewhere will continue to become hotter and more dangerous.

Heatwaves are one of the biggest threats posed by climate change. High temperatures are responsible for thousands of deaths across the world every year, many of which go under-reported. Despite this overwhelming evidence, there is still little public awareness of the dangers that extreme temperatures present to human health."

To request an interview with a Climate Central scientist, please contact Peter Girard at pgirard@climatecentral.org

Context: Climate Change and Heatwaves

Heatwaves have increased in frequency, duration and intensity in almost all regions of the world. Heatwaves that occurred once every 10 years in the pre-industrial climate are now expected once every 3.5 years due to global warming, according to the IPCC report, as noted in the World Weather Attribution media guide.

Exposure to unprecedented heat poses a major threat to people’s livelihoods, with implications for human health.

Europe is one of the fastest-warming regions in the world (IPCC WG1). Heatwaves in Europe in 2003, 2010, 2015, 2017, 2018 and 2019 have all been specifically found to have been made more likely and intense because of climate change. In April 2023, a study by the World Weather Attribution group of climate scientists concluded that the early extreme heat occurring in Spain and Portugal was “almost impossible without climate change.”

Reporting Resources

The global Climate Shift Index map tool shows the influence of climate change on daily average temperatures across the globe.
Temperature data and Climate Shift Index values for 500 regional cities between July 14 and July 17 (CSV file)
Guide to reporting on extreme heat and climate change from World Weather Attribution
Extreme Weather Toolkit: Extreme Heat from Climate Central

Recent coverage of our alerts include the Spain heat in early July (find the alert here), the U.S. Texas and Southwest heat in June/July (find the alert here) and India’s heat wave in June.

About the Climate Shift Index

Climate Central’s Climate Shift Index, grounded in the latest peer-reviewed science, maps the influence of climate change on temperatures across the globe, every day.

Climate Shift Index levels indicate how much human-caused climate change has altered the frequency of daily temperatures at a particular location. Level 1 indicates that climate change is detectable in that day’s temperature. Level 2 means that climate change made exceptionally warm temperatures in a given location at least twice as likely. Level 5 is the maximum and indicates temperatures at least 5 times more likely because of climate change.

For this analysis, temperatures come from NOAA’s Global Forecast System model.