1899 San Ciriaco hurricane, also known as the 1899 Puerto Rico Hurricane, was the longest-lived Atlantic hurricane on record. The third tropical cyclone and first major hurricane of the season, this storm was first observed southwest of Cape Verde on August 3. It slowly strengthened while heading steadily west-northwestward across the Atlantic Ocean and reached hurricane status by late on August 5. During the following 48 hours, it deepened further, reaching Category 4 on the modern day Saffir–Simpson hurricane wind scale (SSHWS) before crossing the Leeward Islands on August 7. Later that day, the storm peaked winds of 150 mph (240 km/h). The storm weakened slightly before making landfall in Guayama, Puerto Rico with winds of 140 mph (220 km/h) on August 8. Several hours later, it emerged