how often does the sea of galilee turn red

The Sea of Galilee turns red very rarely, with notable recent occurrences including August 2025. This phenomenon is caused by a natural bloom of the green microalgae Botryococcus braunii, which produces a red pigment when exposed to intense sunlight. Such algae blooms are not common but can happen more frequently due to rising water temperatures and nutrient conditions influenced by climate change. Authorities note that this red discoloration is harmless and the water remains safe. Past incidents of similar algae blooms have also been reported but remain sporadic rather than regular. In summary, the Sea of Galilee turning red is an unusual and infrequent event caused by natural algae blooms, with no fixed or predictable frequency, although it may become slightly more common with environmental changes.