On November 11, the Sun had a major solar flare of class X5.1, causing radio blackouts in Africa and Europe and announcing geomagnetic storms.

On the morning of November 11, the Sun erupted spectacularly, generating a solar explosion of class X5.1, the strongest in 2025 and the most intense since October 2024, according to Space.com. The eruption occurred at 10:00 GMT (12:00, Romania time) from the solar spot AR4274, which has been extremely active recently. This explosion caused strong radio blackout (R3 level) in Africa and Europe, affecting high-frequency radio communications.

AR4274 also generated other intense eruptions in the previous days, including one of magnitude X1.7 on November 9 and one of magnitude X1.2 on November 10. These eruptions were accompanied by coronal mass ejections (CMEs) that could affect Earth, causing strong geomagnetic storm conditions (G3) and possible extensive auroras. The CME emitted on November 11 is traveling at a speed of 7.1 million miles per hour and could reach Earth on November 12, with the risk of generating severe geomagnetic storms (G4).

Solar eruptions are classified based on intensity, and those of class X are the strongest. The X5.1 eruption sent a wave of X-rays and extreme ultraviolet radiation, ionizing the upper atmosphere and causing significant degradation of the radio signal. This intense solar activity marks a peak in Solar Cycle 25, and NOAA warns that geomagnetic storms could occur in the coming days.