The 1900 Atlantic hurricane season featured the "Galveston hurricane", the deadliest natural disaster in the history of the United States. seven known tropical cyclones, three of which made landfall in the United States. The first system was initially observed over the eastern Atlantic Ocean on August 27. The final storm transitioned into an extratropical cyclone on October 29. These dates fall within the period with the most tropical cyclone activity in the Atlantic. Every storm of the season except the seventh system existed simultaneously with another tropical cyclone.