Why is the minimum wind speed of a hurricane 74 mph and not 75 mph?
This is a good question. I don’t recall anyone asking me this question before. The simple answer is that 74 mph is defined by the Saffir-Simpson Scale as the threshold for a Category 1 hurricane. Most people think that this is a quantitative measure of hurricane strength. But actually it is only a qualitative description of the relationship between hurricane winds and the resultant damage. For example, just think of speeding limits. On some highways, the speed limit is 75 mph. Why it is 75 mph but not 74 mph or 76 mph? Again, this is a qualitative measure. It only means that when your speed is up to this number it becomes dangerous. But we need to draw a line so that police can issue you a ticket. In terms of danger, there is no big difference between 74 mph and 76 mph. But you will get a ticket when you drive 76 mph. The same concept applies for hurricanes. Winds at 73 mph and 74 mph will cause similar damage, but they are defined as a tropical storm and a Cat-1 hurricane, respectivel
