The 1970 Bhola cyclone was the strongest storm of the 1970 North Indian Ocean cyclone season . The 1970 Bhola cyclone was not the most powerful of these , however ; the 1991 Bangladesh cyclone was significantly stronger when it made landfall in the same general area with 250 k winds , a high-end Category 4 . The 1970 cyclone is nonetheless the deadliest tropical cyclone on record and is one of the deadliest natural disasters in recent history .