Europe experiences widespread flooding and severe heatwaves in 2023

The report provides descriptions and analysis of climate conditions and variations from across the Earth system, key events and their impacts, and a discussion of climate policy and action with a focus on human health. The ESOTC also includes updates on the long-term evolution of key Climate Indicators.

Key findings regarding temperatures in Europe:

• 2023 was the joint warmest or second warmest year on record depending on the dataset.
• Temperatures in Europe were above average for 11 months of the year, including the warmest September on record.
• 2023 saw a record number of days with ‘extreme heat stress’. There is an increasing trend in the number of days with at least ‘strong heat stress’ across Europe.
• Heat-related mortality has increased by around 30% in the past 20 years and heat-related deaths are estimated to have increased in 94% of the European regions monitored.

 
Key findings – European climate policy and action for health:

• The number of adverse health impacts related to extreme weather and climate events is rising.
• Evidence from the last decade shows generally good awareness but a low-risk perception of heat by the public, vulnerable groups and some health care providers.
• Initiatives such as the WMO Regional Climate Centre’s Climate Watch System, and other early warning systems, raise awareness of predicted extreme events to enhance societal preparedness.
• Health risk and adaptation differ between countries.
• Tailored climate services for the health sector are effective in increasing resilience, with significant potential for further development.
• Health adaptation can build on established health system infrastructures, but progress has been limited.

 
Key findings for the European ocean:

• For the year as a whole, the average sea surface temperature for the ocean across Europe was the highest on record.
• In June, the Atlantic Ocean west of Ireland and around the United Kingdom was impacted by a marine heatwave that was classified as ‘extreme’ and in some areas ‘beyond extreme’, with sea surface temperatures as much as 5°C above average.

 
Key findings regarding hydrological variables in Europe:

• During 2023, Europe as a whole saw around 7% more precipitation than average.
• Averaged across the European river network, river flows were the highest on record for December, with ‘exceptionally high’ flow in almost a quarter of the river network.
• During 2023, one third of the European river network saw river flows exceeding the ‘high’ flood threshold, and 16% exceeding the ‘severe’ flood threshold.

 
Key findings – renewable energy resources:

• The year saw a record proportion of actual electricity generation by renewables in Europe, at 43%.
• Increased storm activity through October to December resulted in above-average potential for wind power production.
• Potential for run-of-river hydropower generation was above average across much of Europe for the year as a whole, linked to above-average precipitation and river flow.
• For the year as a whole, potential for solar photovoltaic power generation was below average in northwestern and central Europe, and above average in southwestern and southern Europe, and Fennoscandia.

 
Key findings for snow and glaciers in Europe:

• Much of Europe experienced fewer days with snow than average, particularly across central Europe and the Alps during winter and spring.
• The Alps saw exceptional glacier ice loss in 2023, linked to below-average winter snow accumulation and strong summer melt due to heatwaves.
• Over 2022 and 2023, glaciers in the Alps have lost around 10% of their remaining volume.

 
Key findings – Arctic region:

• The year was the sixth warmest on record for the Arctic as a whole. For Arctic land, it was the fifth warmest, closely behind 2022. The five warmest years on record for Arctic land have all occurred since 2016.
• Arctic Sea ice extent remained below average through most of 2023. At its annual maximum in March, the monthly extent was 4% below average, ranking fifth lowest on record. At its annual minimum in September, the monthly extent ranked sixth lowest, at 18% below average.
• Total wildfire carbon emissions from the sub-Arctic and Arctic regions were the second highest on record. Most high-latitude wildfires occurred in Canada between May and September.