Looking back on C3S summer 2024 | Travel

September 30, 2024

Summer 2024 was the warmest on document for Europe.
Temperatures diversified throughout the continent, with near or beneath common temperatures within the northwest, whereas southeastern Europe and northern Fennoscandia noticed their warmest summer on document.
Parts of Europe noticed substantial heatwaves through the season. Southeastern Europe noticed as much as 60% extra ‘warm daytimes’ than common.
Southeastern Europe skilled ‘strong heat stress’, the place the every day most feels-like temperature reached at the least 32°C, for round two thirds of the summer interval. At 66 days, that is the very best variety of ‘strong heat stress’ days on document, by a big margin.
The sea floor temperature (SST) averaged over the entire Mediterranean Sea reached record-high every day values in August, breaking the information from July 2023.
While many of the continent had a below-average variety of moist days, notably the southeast, different areas, together with the northern UK, Fennoscandia and the Baltic nations, noticed as much as 20 extra moist days than common.
35% of European rivers have been notably or exceptionally low, particularly within the southeast, whereas a lot of central Europe noticed exceptionally excessive common river flows for the time of yr.

Surface air temperature and warmth stress

The common floor air temperature over European land for summer (June–August) 2024 was the very best on document for the season at 1.54°C above the 1991-2020 common. The three summer months every ranked second warmest on document for the month in query (joint-second for June), with very related anomalies (1.57°C above common in June and August, 1.49°C in July).

Summer 2024 exceeded the earlier air temperature document, set in summer 2022, by 0.2°C.

Seasonal common temperatures have been predominantly above common over virtually the entire continent, with record-high temperatures in southeastern Europe and northern Fennoscandia. In stark distinction, some areas within the western a part of the continent, together with Iceland, Ireland, northern and western components of the United Kingdom (which total skilled its coolest summer since 2015), and southern Norway have been cooler than common.

The seasonal averages largely replicate the temperature distribution noticed in July and August, whereas in June, a comparably bigger space of western Europe skilled colder-than-average temperatures.

Parts of Europe noticed substantial heatwaves through the summer. For instance, in June, southern Italy, southeastern Europe and Türkiye have been impacted by a heatwave, with temperatures reaching 40°C in lots of areas, and native temperature information damaged. In July, heatwaves affected Italy, Greece, and Bulgaria, whereas in August, a lot of southeastern Europe, together with Italy, Portugal, and Spain, skilled related circumstances. For extra data on month-to-month variations in temperature anomalies, see the month-to-month bulletins of June, July and August.

The impact of the heatwaves is mirrored in an above-average variety of ‘warm daytimes’ over a lot of Europe all through summer.

In explicit, southern Italy, the Balkans, Greece and western Türkiye noticed above-average heat daytimes all through the season, with as much as round 60% greater than the summer common over the reference interval 1991–2020. Among different areas, the Iberian Peninsula, had 15% above-average heat daytimes, principally owing to circumstances noticed in July and August.

Parts of Spain, Italy and southeastern Europe additionally skilled an above-average variety of ‘tropical nights’. Periods of heat that see excessive daytime temperatures, notably mixed with tropical nights, can result in warmth stress, a situation the place the physique struggles to chill itself down.

Thermal consolation, together with warmth stress, could be monitored utilizing indices such because the Universal Thermal Climate Index (UTCI), which considers temperature, humidity, wind pace, sunshine and warmth emitted by the environment, and the way the human physique responds to totally different thermal environments. It can be utilized to deduce weather-induced out of doors thermal stress in people by classifying UTCI values into ten totally different warmth and chilly stress classes, with items of °C representing a ‘feels-like temperature’.

‘Strong heat stress’ days

‘Very strong heat stress’ days

During summer 2024, the common every day most feels-like temperature, calculated primarily based on the Universal Thermal Climate Index (UTCI), for Europe was 2.1°C above common, the very best on document for the continent.

Large components of southern Europe noticed the equal of two full months with “strong heat stress”, reaching 60 days in complete over the season. Just a few areas in Greece and western Türkiye noticed ‘strong heat stress’ on day-after-day of the summer, and round two months of ‘very strong heat stress’ . ‘Very strong heat stress’ was skilled throughout a lot of southern and jap Europe, and ‘extreme heat stress’ occurred in some small areas in Spain and western Türkiye.

For southeastern Europe as an entire, the common variety of summer days with at the least ‘strong heat stress’ is 29. Summer 2024 noticed a document variety of ‘strong heat stress’ days for this area, at 66 days, 37 greater than common (round 29 days), whereas the summer common every day most UTCI reached the document worth of three.3°C above common.

Maximum feels-like temperature

Daily most Universal Thermal Climate Index (UTCI) on every day of July and August 2024 throughout Europe, indicating the utmost feels-like temperature (°C). Only values exceeding 26°C, the edge for ‘moderate heat stress’ are proven. Data: ERA5-HEAT. Credit: C3S/ECMWF

Daily sea floor temperatures (SSTs) averaged over the entire Mediterranean Sea reached their highest values on document in mid-August, with a peak of 28.45°C on 13 August, in response to information from ERA5. This broke the earlier document of 28.20°C from July 2023. Note that the exact date and values of the information can fluctuate barely between SST datasets (the Copernicus Marine Service reported a document of 28.47°C on 15 August). However, there may be basic settlement amongst datasets that every day information have been damaged in August 2024.

Averaged over the summer 2024, SSTs have been above common all over the place within the Mediterranean however solely reached document highs in the Adriatic Sea and the jap components of the area. Beyond the Mediterranean, the Norwegian Sea off the central coast of Norway additionally noticed document temperatures for the season as an entire. In distinction, cooler than common SSTs have been noticed within the northeastern Atlantic west of the Iberian peninsula, north of Ireland, and round Iceland.

Precipitation was variable throughout the season and the continent. In June, it was predominantly above-average in many of the western and northern areas, whereas southeastern areas and the UK and Ireland noticed beneath common values. In July, the areas displaying precipitation deficit prolonged to the north and east together with Ukraine. In August, most of continental Europe in addition to southern UK and Ireland was drier than common. Most of the Mediterranean area and Eastern Europe noticed an absence of precipitation, and drier-than-average floor soils, all through the season. The jap Balkans and the areas surrounding the Black Sea skilled drought circumstances, affecting water availability and agriculture.

For the season as an entire, over components of northern UK and Ireland, Fennoscandia and the Baltic Countries the variety of moist days was greater than regular, reaching as much as 10 days, and round 15 days above common for Norway and northern Sweden. A big area together with Italy and lengthening northeastward via the Balkan Peninsula to Ukraine noticed below-average moist days.

Several areas skilled extreme precipitation occasions over summer. The 5 consecutive day most precipitation exhibits the above common sign, of as much as 80 mm, of the heavy rainfall occasions noticed in June in northern Italy and components of the states Baden-Württemberg and Bavaria in southern Germany (see additionally the river circulation seasonal map). This latter occasion was triggered by circumstances generally known as Vb (five-B), with a low stress system pushing moisture-rich air from the Mediterranean area northward, over the Alps. The comparably sturdy moist anomaly over the Baltic nations, arose from the heavy precipitation introduced by storm Kirsti, on the finish of July.

Summer-average river flows have been notably or exceptionally low in 35% of European rivers, particularly within the southeast. The areas affected are per these most impacted by heatwaves and low precipitation. The Copernicus Emergency Management Service (CEMS) European Drought Observatory (EDO) had warnings in place throughout the summer for persistent and stable drought conditions in southern and jap Europe. Much of central Europe noticed exceptionally excessive common river flows for the time of yr, per areas that noticed most precipitation and extra moist days than regular. In June 2024, southern Germany confronted substantial flooding in the states of Bavaria and Baden-Wuerttemberg.

C3S want to thank the broader Copernicus and NMHS group, notably KNMI and DWD, for his or her analyses and collaboration on this seasonal overview.