1899 San Ciriaco hurricane
Hurricane San Ciriaco set many records on its path. Resulting in at least 3,369 deaths in Puerto Rico, the storm was the deadliest hurricane to hit the island and the strongest at the time, until the Hurricane San Felipe Segundo made landfall in 1928 as a Category 5 hurricane. It was also among the deadliest Atlantic hurricanes ever recorded.
1985 Puerto Rico floods
The most intense rainfall occurred on October 6, and on that day two stations recorded 24-hour precipitation totals exceeding . These totals broke the 24-hour rainfall records set during the 1899 San Ciriaco hurricane, and amounted to nearly half of the annual precipitation totals. The town of Peñuelas reported very high rainfall totals in a short amount of time, including in one hour and in two hours. The highest rainfall total on Puerto Rico was in Toro Negro State Forest. Rainfall spread across the island, and the southern half of Puerto Rico experienced totals of over . Rainfall totals over spread across the United States Virgin Islands. The tropical wave later spawned a low pressure area north of Hispaniola that became Tropical Storm Isabel on October 7, a day before the rains subsided in Puerto Rico. The storm ultimately struck Florida before dissipating on October 15.