Abstract <p>Powerful transient processes on the Sun lead to solar storms and to geospace storms on Earth. Ionospheric storms are an integral part of geospace storms; they are extreme manifestations of ionospheric weather. Its variations have a significant impact on the functioning of civilization. It has been established that the manifestations of storms significantly depend not only on the characteristics of solar and geospace storms but also on the season, time of day, magnetic and geographical coordinates, etc. All this determines the relevance of studying each new ionospheric storm, especially when it comes to unique events. The purpose of this work is to study the features of the global manifestation of a unique geospace storm on May 10–13, 2024, in the F region of the ionosphere. The main features of the global manifestation of a unique geospace storm on May 10–13, 2024, in the F region of the ionosphere have been studied. The largest negative disturbances were observed on May 11, 2024, during the recovery phase of the geomagnetic storm. At most stations, the storm was strong or severe during the daytime. At night, manifestations of strong, severe, and extreme storms were mainly observed. The storm of May 13, 2024, was less intense compared to the storm of May 11, 2024. During the daytime, it was minor and moderate, while it was mainly strong and even severe at night. Negative and positive ionospheric storms sometimes replaced each other. Positive ionospheric storms were weaker. The duration of the blackout tended to decrease with decreasing geographical latitude of the station.</p>