1867 Atlantic hurricane season

The 1867 Atlantic hurricane season featured the San Narciso hurricane, one of the deadliest tropical cyclones to impact the Virgin Islands and Puerto Rico. A total of nine known tropical systems developed during the season, with the earliest existing by June 21 and the last dissipating on October 31. Of the ninth cyclones, seven intensified into hurricanes, one of which became a major hurricane. However, in the absence of modern satellite and other remote-sensing technologies, only storms that affected populated land areas or encountered ships at sea were recorded, so the actual total could be higher. An undercount bias of zero to six tropical cyclones per year between 1851 and 1885 and zero to four per year between 1886 and 1910 has been estimated.

Of the known 1867 cyclones, the third, fourth, fifth, and eight systems were first documented in 1995 by meteorologists José Fernández-Partagás and Henry F. Diaz. The first storm was identified in 2003 by Cary Mock and subsequently added to the official hurricane database (HURDAT) by the Atlantic hurricane reanalysis project. Neither Fernández-Partagás and Diaz nor the Atlantic hurricane reanalysis project could reconstruct tracks for the third, fifth, and eight cyclones, instead using only a single location point. However, a more recent study, published in 2014 and authored by climate scientist Michael Chenoweth, extended the tracks of several storms and proposed the addition of four systems not currently included in HURDAT, though these changes have yet to be approved.

The most intense cyclone of the season, the ninth storm, also known as the San Narciso hurricane, peaked as a Category 3 hurricane on the modern-day Saffir–Simpson scale with maximum sustained winds of 125 mph (205 km/h) in late October. Striking the Leeward Islands and Puerto Rico at Category 3 intensity and later the Dominican Republic as a Category 1 hurricane, the cyclone killed approximately 1,050 people, more than half on or just offshore Saint Thomas. Puerto Rico alone reported at least $1 million (1867 USD) in damage. Several other storms impacted land, with the first cyclone causing wind damage in coastal Georgia and South Carolina and crop losses over eastern North Carolina. Some wind and erosion damage occurred in coastal areas of Massachusetts due to the second storm, which also drowned 13 people due to maritime incidents. Additionally, the season's seventh cyclone severely impacted areas of Tamaulipas, Texas, and Louisiana near the Gulf of Mexico, with at least 27 fatalities, all but one in Tamaulipas.