Strong geomagnetic storm causes auroras over Central Europe
Auroras also possible in Austria on Wednesday night. During the night from Tuesday to Wednesday (11/12 November 2025), a strong geomagnetic storm caused auroras even in relatively southern regions of the Earth, such as Central Europe and Florida. Auroras were also visible in Austria.
‘The solar storm reached Earth at 11:38 p.m. on Tuesday. It triggered the strongest geomagnetic storm of 2025 to date and the third strongest in the current solar cycle. The strength of this geomagnetic storm was G4 on the five-part G scale,’ says Christian Möstl, head of the Space Weather Office at GeoSphere Austria. ‘The effects were particularly intense because a fast solar storm followed immediately after an earlier solar storm, reaching Earth even faster in a kind of slipstream. In addition, these two solar storms interacted shortly before reaching Earth. Polar lights are also possible in Austria on Wednesday night, as another solar storm is expected to reach Earth on Wednesday. In the wake of geomagnetic storms, problems with positioning using global navigation satellite systems cannot be ruled out.’
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Aurora borealis over Austria. Taken on the night of 12 November 2025 at the Sonnblick Observatory of GeoSphere Austria. © GeoSphere Austria/Scheer.
The weather will allow a clear view of the starry sky across most of Austria tonight. However, there will be dense fog patches in some low-lying areas.
The reason for the relatively large number of auroras in 2024 and 2025 lies in natural fluctuations in the sun. ‘We are currently at the peak of the so-called 11-year solar cycle. In this phase, the sun forms more magnetic fields, which are visible as sunspots. This phase is expected to continue until 2026. From 2027 onwards, it will weaken again until the next cycle begins in the early 2030s,’ explains Christian Möstl from the Space Weather Office at GeoSphere Austria.
The sun constantly emits radiation and charged particles into space. During a solar flare (solar storm), the sun ejects a large amount of particles within a short period of time, together with strong magnetic fields. When a solar storm hits the Earth's magnetic field, it can cause auroras and, in extreme cases, disrupt satellites, navigation systems and power grids.
In order to provide timely warnings of such events, the Space Weather Office at GeoSphere Austria in Graz is working on innovative methods for real-time prediction of solar storms and is now one of the world's leading organisations in this field.
Translated with DeepL.com (free version)