The Expert’s View — Joris Royet, Weather Project Manager
“The meteorological summer of 2026 was marked by several severe thunderstorm outbreaks across Europe. Multiple weather patterns favoured the development of supercells capable of producing large hail, destructive wind gusts and locally even tornadoes.
Electrical activity was particularly concentrated during the second half of June and throughout an exceptionally active August, when several intense thunderstorm waves affected large parts of Europe.
Italy once again ranked among the most lightning-prone countries in Europe, benefiting from strong summer instability, Mediterranean air masses and topographic effects that frequently trigger thunderstorms.
Conversely, Portugal and southwestern Spain experienced relatively limited lightning activity. Atmospheric patterns often favoured thunderstorm development ahead of weather systems rather than directly over these regions.
While summer 2026 does not rank among the most lightning-active summers of recent years, it clearly stands above summer 2025, which was marked by particularly low lightning activity.”

European Summer 2026
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Terminology

To help you better understand the information in this report, here are the definitions for some of the most frequently used terms.

Cloud-to-ground (CG) lightning flash

Discharge of current of a certain intensity circulating between the cloud and the ground. Abbreviated to CG (Cloud-to-Ground).

Lightning density

The best current representation of thunderstorm activity is lightning density, which is the number of cloud-to-ground (CG) lightning flashes per km² per year.

Lightning flash

All current discharges and electrical impulses from a lightning event. A lightning flash can occur within the same cloud (IC), between a cloud and the ground (CG) or between two clouds (CC). A lightning flash can be composed of one stroke or many strokes, which are current discharges and electrical impulses.

Thunder day

Each day that lightning was detected in a given area.

About this lightning report

The lightning report is based on data provided by the METEORAGE network.

The information we provide concerns cloud-to-ground (CG) lightning flashes and lightning density.

To be able to compare these data with the data collected, METEORAGE counts the main current pulse circulating between the cloud and the ground, defined in this report by the term “Cloud-to-ground (CG) lightning flash”.

Our expertise draws on more than ten years of analysis, observation and data collected in Europe, and more broadly worldwide. We have over 37 years’ expertise in France.

The performance of our network has been validated scientifically and delivers the best possible results with:

  • > 98% lightning flash detection,
  • a median detection accuracy of 100 meters,
  • > 90% distinction made between cloud-to-ground (CG) lightning flashes and intra-cloud lightning flashes.

The METEORAGE network consists of more than 100 lightning sensors, calculators and a processing system that manages the databases. Our lightning sensors are based on the Vaisala technology, currently considered one of the best in the world. Our network achieves levels of performance validated by numerous scientific studies and publications.