Skirting the extreme western coast of Cuba on October 13, the storm produced gusts estimated at in Pinar del Río Province. The highest measured sustained winds were in Guane and at Rancho-Boyeros Airport in the capital city of Havana. Additionally, pressures at the city fell to 979 mbar (hPa; ). Heavy rains caused rivers to over-top their banks, forcing thousands of people to evacuate. Three fatalities occurred in Guane due to collapsing homes. A fourth fatality took place elsewhere in Cuba. Numerous homes were damaged or destroyed by the storm, with exact numbers unknown. The region's tobacco crop also sustained considerable losses with fields and warehouses destroyed. The damage to agriculture compounded economic losses in Cuba that resulted from Hurricane Flora in September 1963, which devastated the nation, as well as impacts from Hurricanes Cleo and Hilda earlier in 1964. The combined effects of Cleo, Hilda, and Isbell resulted in economic losses of approximately $100 million in the country, of which at least $20 million was directly attributed to Isbell.
