The European sky is showing a new way to hail: fewer episodes in the overall count, but with stones of greater size and destructive capacity. This reconfiguration, directly linked to the global warming, forces us to rethink how we protect crops, infrastructure and the population from severe storms.
The apparent paradox of “less, but more violent” It has a physical basis. The rising melting level in the atmosphere melts small hail before it hits the ground, while in more intense storms, powerful updrafts and abundant supercooled water allow some stones to grow larger for longer within the cloud, increasing their final size and damage potential.
What is changing in hail formation?
Hail is born in highly developed storms where raindrops are propelled into cold layers and freeze, forming ice nuclei. These particles encounter supercooled water again and add layers as they rise and fall within the cloud.
This cycle of collisions and instant freezing It is repeated until the stone reaches a weight that the updraft can no longer support. Its final size depends on the strength of the updraft, the availability of moisture, and the thickness of the stone. warm layer that must be crossed when falling.
The highest fusion level, a lot of small hail melts before reaching the ground, reducing the number of observed events. However, when favorable ingredients coincide, some stones grow a lot and manage to survive the fall.
This change doesn't just mean fewer alarms; it means potentially greater impacts when severe storms develop with the right structure to produce large hail.
An uneven pattern on the European map
Analysis indicates that the Northeast Europe could see a slight increase in summer hailstorms, while the southwest and central areas would tend to record fewer episodes. Despite this, in many regions the probability of larger stones.
Risk is not linear: damage grows in a exponential with the extreme sizeA 5 cm stone doesn't duplicate the impact of a 2,5 cm stone; it can multiply it several times over, with much more severe consequences for property and crops.
Operationally, few giant hail events can exceed losses in seasons with numerous smaller hailstorms. This asymmetry complicates risk management and insurance planning.
Most exposed sectors and rising costs
La farming It is the most vulnerable sector: vineyards, fruit trees, and vegetables can be devastated in minutes. Vehicles are also affected. solar, roofs and greenhouses, increasing the cost of claims and putting pressure on insurers.
In Spain, 2025 left notable episodes: in June more than were damaged 415.000 hectares insured, with Castile and León as one of the most affected communities. At the end of July, a storm in Murcia impacted more than 8.500 hectares of almond, peach and vegetable trees, with losses exceeding 10 millones de euros.
That same period, in the Castellón's Lower Plain, another hailstorm caused millions of dollars in damage to crops and vehicles, leading several municipalities to request a declaration of disaster zone.
Beyond the economic cost, large hail is a security problem For people and animals, it can break glass, clog drains when it coincides with heavy rains, and complicate emergency response.
The increase in severity has forced insurers and administrations to mobilize expert reports, activate aid, and improve the communication of alerts in the event of high-impact convective storms.
Adapt and anticipate: key measures and recent science
In the face of changing risks, continuing with plans based on the past is insufficient. It is urgent to update risk maps to reflect not only frequency, but potential severity, and review building regulations encouraging more resistant materials in roofs, glazing and installations of solar energy.
- Recalibrating insurance models to incorporate the severity jump of large hail.
- Constructive reinforcement in areas of greater exposure and hail nets in high-value crops.
- Better observation and reporting with dense networks and homogeneous hail-size metrics.
- Climate mitigation: reduce emissions to curb the forcings that fuel severe storms.
The latest research by Newcastle University, in collaboration with the Met Office and University of Bristol, using high-resolution simulations under high emissions scenarios, concludes a scenario of fewer hailstorms but with larger stones, with particular exposure in southern Europe. The study indicates a greater probability of hail >5 cm in the Mediterranean and Italy, especially in autumn and winter, and decreases in the central, northern and British Isles.
Although they persist uncertainties Regarding how the greater melting at altitude conditions the extreme size, the recommendation is clear: reinforce the preparation, better profile warm-origin storms and improve warning systems to reduce very severe local impacts.
Europe is entering a phase in which hailstorms will probably be less common but more harmfulUnderstanding the physical mechanisms, mapping regional inequality, protecting critical sectors, and advancing mitigation will make the difference between manageable damage and extraordinary losses in the coming years.
