As of 20 January 2024, 9627 large hail (2+ cm) reports were submitted to the European Severe Weather Database for the year 2023. Out of these, 1931 reports involved very large (5+ cm), and 92 reports involved giant (10+ cm) hail. All three metrics were the highest ever recorded in the database, making 2023 the third record-breaking hail season in a row. Besides the raw numbers of reports, the number of days with each hail size category was also record-breaking. There were 229 days with large, 96 days with very large, and 13 days with giant hail. The relative difference in the number of reports to the other years was larger than for the number of days with a certain hail size. One likely reason is the ESSL and cooperating observers/observer networks becoming more efficient at collecting reports. Another reason can be that 2023 involved more very long-tracked hailstorms which produced large hail at many locations. For example in 2022, there were 5 hailstorms with hail swaths exceeding 200 km. In 2023, there were 13 such hailstorms, with one particularly long-lived supercell producing a 686 km long hail swath affecting 5 countries.

The country with the highest number of large hail reports was France (1502), closely followed by Italy with 1468 reports. However, in terms of the most damaging hailstorms, Italy took the commanding lead with 596 reports of very large, and 67 reports of giant hail, compared to 280 and 10 over France. 30.9% of very large and 72.8% of giant hail reports were submitted for Italy. The third most affected country by large hail was Germany with 1270 reports, out of which 142 involved very large hail. 

Records were broken not just concerning the amounts of large and very large hail, but also in terms of the maximum hail sizes. Europe’s largest (photographed) hail record was broken twice in a mere 5 days in Italy. On 19 July, 16 cm hailstone was reported (see ESSL news item), followed by 19 cm hail on 24 July (see ESSL news item). In both cases, hail sizes were estimated using reference objects placed near the hailstones. The heaviest officially weighted hailstone also fell on 24 July with a scale reading 484 g. The hailstone had a diameter of 13 cm and thus the largest hailstones observed on 19 or 24 July likely weighed considerably more. Giant hail fell also in other countries: Slovenia (the largest hail reaching 13.8 cm), Bulgaria (13 cm), Croatia (13 cm), France (11 cm), Spain (11 cm), Bosnia (11 cm), Germany (10 cm) and Russia (10 cm).

Large hail had pronounced societal and economic impacts. At least 328 people were injured by hail, the real number likely being much higher as the lighter injuries caused by hail are not well covered by media. Most of the injuries (242) were reported from Italy. Hail also caused tremendous economic damage. Munich-RE report stated that Italian hailstorms cost billions of $ and the Gallagher-RE report put the figure to 3 billion $ with the overall damage cost for the convective storms in Europe at approximately 12 billion $.

Below, we present an overview of the (subjectively chosen) major hail cases in Europe. Please note that severe hailstorms occurred also outside of the chosen dates and not all of them are mentioned here. If you feel we’ve missed a particularly important case, let us know at tomas.pucik@essl.org. Very importantly, ESSL would like to express gratefulness to the Voluntary Observer Persons and Voluntary Observer Networks, who have significantly contributed to the record number of hail reports collected during this year. Their list can be found here.

Cases

6 July: Damaging hailstorms affected Spain and Italy. An 11 cm large hail fell in Herrera de los Navarros, damaging cars, their windshields, and roofs. Hail measuring 10 cm in diameter fell in several locations along the hail swath. This was the first storm to produce giant hail in Europe in 2023. Several other hailstorms affected Euskadi province. Hail reached up to 7 cm, causing 11 injuries in the town of Vitoria-Gasteiz and widespread damage to vehicles. In northwestern Italy, hail reached 6 cm and damaged numerous cars.

11 July:  Many countries were affected by large hail with reports received from France, Germany, Switzerland, Italy, Austria, and Slovenia. France was the most affected with 258 reports. The largest hail fell in Neulise, reaching 10 cm in diameter, damaging roofs and cars. Supercells over France eventually grew upscale, resulting in a convective windstorm that traveled across northern Switzerland and southern Germany. Several hailstorms also formed over the southern Alps. 9.5 cm large hail fell in Bolzano province, Italy, which is a rare occurrence within the interior of the mountains. In Austria, hail up to 7 cm in diameter fell in Kärnten province. 

12 July: Severe hailstorms affected France, Germany, Switzerland, and Italy. In France, hailstorms impacted the Rhône-Alpes region with the biggest hail estimated at 8.5 cm across. In Switzerland, hail was up to 6 cm across and the largest hail, estimated to be 10 cm across,  fell in northern Italy, in Angolo Terme. The late evening hailstorms grew upscale, resulting in a damaging convective windstorm across northeastern Italy, Slovenia, and southern Austria. The highest measured wind gust reached 48.9 m/s. 

13 July: Perhaps one of the most long-lived supercell hailstorms ever observed in Europe occurred on that day. The storm affected Slovenia, Croatia, Hungary, Serbia, and Romania, making it a “5-state hailstorm”, tracking for 686 km and lasting 9 hours and 15 minutes. The storm formed around 12 UTC in Slovenia, where it produced the largest hail, measured at 13.8 cm across, in Gorenja Lepa Vas. In Hungary, the supercell produced hail up to 5 cm across, and in Croatia, up to 6.5 cm across. The storm continued through Serbia and eastern Romania, producing hail up to 7 cm in diameter, dissipating after 21 UTC. Hail was wind-driven in many places, causing significant damage to roofs, cars, windows, facades of houses, and agriculture. In Vrbas, Serbia, at least 50 people were injured by hail.

19 July: Severe hailstorms affected Germany, Switzerland, Italy, Slovenia, Croatia, Bosnia, Serbia, Slovakia, Poland and Romania. Altogether, 447 hail reports were received in the ESWD and 4 separate hailstorms produced hail ≥ 10 cm across with 27 separate reports of hail of that size. Two of the giant-hail-producing storms also involved large hail tracks over 200 km long. The event started with a supercell forming on a southwestern flank of the convective system over Slovenia, tracking over Croatia, and dissipating over Bosnia. In Slovenia, the hail reached 9 cm in diameter. Over Croatia, the largest hail, measured at 13 cm in diameter, fell in Ribnik, and hundreds of roofs were destroyed in the Karlovac area. Over southeastern Slovakia, a supercell produced wind-driven hail up to 6 cm large, which caused serious damage to roofs, windows, and facades. The most serious impact was over Italy, where three supercells produced hail up to 10, 14 and 16 cm across. The estimated 16 cm hail fell in Carmignano di Brenta and set a new record for the European hail size that involves photographed hailstone. Dozens of villages and towns suffered car, roof, and window damage. At least 111 people were injured by hail here. Besides devastating hail, the event featured a derecho with an almost 1000 km long damage path that crossed southern Austria, Slovenia, Croatia, and Serbia and dissipated over southwestern Romania and northwestern Bulgaria. 

21 July: Multiple severe hailstorms were observed over Italy, Slovenia, Croatia, Bosnia, and Hungary. The situation started with an overnight hailstorm in Lombardia, Italy, with the largest hail measuring 13 cm and weighing 365 grams. In the afternoon a hailstorm in Bosnia produced an 11 cm large hailstone that fell in Prnjavor. In southwestern Hungary, wind-driven hail up to 9 cm large caused extensive damage to agriculture, roofs, and windows of houses. 

22 July: Another day with severe hailstorms over Italy, Bosnia, and Serbia. In Serbia, a long-lived supercell produced wind-driven hail up to 9 cm in diameter with severe impact especially in and around Kraljevo. Here, the hail injured at least 2 people with one article mentioning that the emergency room was overwhelmed by people injured by hail there. In Italy, two supercells produced separate hail swaths in Emilia-Romagna. The largest hail, 10 cm across, fell in Terre del Reno. Hail also injured 5 people. The supercell that produced the largest hail also produced an IF3 tornado. The hail swath of the supercell was 230 km long before it moved over the Adriatic Sea. The total swath was likely much longer as the storm kept its intensity (judging by the satellite imagery) moving towards the Croatian coastline.   

24 July: The true  “hail day of the year” with 855 reports of large hail submitted to the ESWD. Large hail was observed across France, Switzerland, Italy, Slovenia, Croatia, Austria, Czechia and Slovakia. The number of hail reports per day almost matched the current record from 24 June 2021, which stands at 858 reports. 33 reports involved hail over 10 cm in diameter. In total, hail injured 119 people, all of them in Italy. 3 hailstorms produced swaths of hail over 300 km long, the longest being 546 km with the storm lasting 6 hours and 40 minutes. The first hailstorms formed in the early morning over France with a maximum hail diameter of 7 cm. The severe weather ramped up in the evening hours. The first hailstorm formed over Lombardia and tracked through the southern part of Lago di Garda, Veneto region, and across the Adriatic Sea to Istria, Croatia. The largest hail reached 12 cm near the lake and wind-driven hail occurred in multiple spots of the hail track. Two more supercells formed over Trento and tracked over Fruli-Venezia Giulia and then to Slovenia. The first produced hail “only” up to 9 cm, but it was wind-driven along much of the path. Extreme damage occurred in Mortegliano and its surroundings, with roofs and car windshields destroyed, house facades damaged, and windows broken. The second supercell produced larger hail with an approximately 50 km long swath of giant, 10+ cm hail. The largest hail fell in Azzano Decino, which was estimated at 19 cm across using the reference objects placed near the hailstone. The hail caused considerable damage, including complete punctures of some of the car windshields. In Slovenia, the hailstorm caused hail up to 10 cm across. It should be noted that Azzano Decino was hit twice by giant hail in a mere 2-year period. 10 cm hail fell in the town in the early morning hours of 1 August 2021. In Slovakia, 8 cm hailstones were reported from the northeastern part of the country.  

25 July: Two intense supercells produced giant, 10+ cm, hail in the overnight to early morning hours over Italy. The largest hail, measuring 12.5 cm in diameter, fell in Castiglione delle Stiviere. The storm that produced the hail copied part of the hail swath from the previous day and also impacted the area to the south of Lago di Garda with giant hail. Severe hailstorm also affected western Ukraine with the largest hail up to 8 cm in diameter.

6 August: Giant hail, up to 13 cm in diameter, was reported from Dulovo, Bulgaria. The hail was driven by severe wind in the area and caused significant damage to cars, roofs, facades, windows, and agriculture. Interestingly, such large hail fell only at one location and other locations received hail only up to 6.5 cm. The wind-driven hail continued into Romania, where the storm transformed into a bow echo with wind gusts up to  

7 August: Multiple supercells formed over Lithuania and moved across Latvia during the morning hours, with one storm affecting southwestern Estonia. In Lithuania, hail reached up to 9 cm, and widespread damage to the cars, windows, roofs, and greenhouses was reported, especially in the Panevėžys area. One person was injured by glass shattered by hail in Vepriai.  In Latvia, the largest hail ever recorded till that time, 8 cm in diameter, fell in Annenieki. In Estonia, the hail reached 8 cm across in Torgu. The highest impact came from a fast-moving and long-lived supercell that covered 380 km distance in 4 hours and 15 minutes as it moved from Lithuania to Estonia. Along much of its path, large hail was driven by severe wind gusts. Over Latvia, particularly in Tukums, Jelgava, and Talsi districts, wind-driven hail of 3 – 6 cm in diameter caused extreme damage to agriculture, forests, cars, windows, and facades of houses. 18 410 ha of farmland was destroyed by the hail. Wind gusts reached up to 32.6 m/s in the path of the storm. A historical castle in Jaunpils had many windows broken by the wind-driven hail, and more damage was caused by the subsequent heavy rainfall. Large hail also injured 3 people and killed or injured a large number of storks, cranes, and other birds. Some of them remain in different care centers because of blindness caused by the large hail damage to the eyes or the necessary amputation of wings due to broken bones. 

22 August: Several supercells produced very large hail over eastern Czechia and southern Poland. The largest hail fell in Klokočov, 8 cm in diameter. Significant damage to roofs, windows, and cars was reported from the area. 

25 August: Very large hail fell in France, Switzerland, Italy, and Austria. The largest hailstone, measured at 9.5 cm across, was found in Bärnbach, Austria. In France, the largest hail reached 7 cm. The worst impact was reported from Ticino, where wind-driven hail up to 7 cm in diameter caused extensive damage to cars, roofs, facades, and windows. An unknown number of people were injured by hail. 

26 August: 316 large hail reports were submitted to the ESWD for this day. Large hail occurred in Spain, Italy, Germany, Austria, Slovakia, Poland and Greece. The event began with supercells developing over Poland and N Slovakia. The largest hail measured 9.5 cm in diameter in Poland and 8 cm in diameter in Slovakia with one hail-related injury. In the afternoon hours, two long-lived supercells formed over Bavaria. The northern one produced hail up to 6 and the southern one hail up to 10 cm in diameter. Hail was wind-driven in both storms and fell in large quantities. The largest impact from the storms was in the Bad Tölz-Wolfratshausen area, where 80% of the roofs suffered serious damage. Besides that, cars, windows, and house facades were heavily damaged. An impressive video of the hailfall can be found here. Hailstorms also had a tragic impact on animals: birds, hares, deer, and calves were reportedly killed by hail. In some areas, 90% of the wildlife was killed or injured by the hail. Several horses on the farm were injured, suffering bone fractures from the hailstone impacts. In Spain, 10 cm large hail fell in La Sènia, Catalonia, injuring one person and causing damage to roofs and cars. 

30 August: Severe hailstorms occurred over Bulgaria, Romania, northeastern Poland, Lithuania, and Latvia. In Lithuania, hail up to 9 cm was found following the storm, and in Latvia, hail up to 8.5 cm in diameter was observed.

17 September: Damaging hailstorms affected Spain and France. Altogether, 5 storms produced hail over 5 cm in diameter. Two storms were particularly noteworthy. The first crossed the Valencia region in Spain. Hail reached 8 cm in diameter, fell in large quantities, and was wind-driven as well. Vineyards and tree orchards were completely devastated. Impressive photos or videos from the event can be found here. Even larger hail occurred in France, northwest of Toulouse, reaching 11 cm across. Roofs, greenhouses, and car windows were destroyed by the hail.