Tropical depressions become tropical storms when maximum winds reach 39 mph. They become hurricanes when winds reach how many miles per hour? (within 3)

The journey of a powerful ocean storm is marked by specific milestones defined by wind speed. Once a tropical depression organizes and its sustained winds reach 39 mph, it earns a name and becomes a tropical storm. The next crucial dividing line, the one that separates a strong tropical storm from a Category 1 hurricane, is a sustained wind speed of 74 miles per hour. This threshold is the official starting point for the Saffir-Simpson Hurricane Wind Scale, the system used to classify these massive storms.

This isn't an arbitrary number; it signifies a fundamental shift in a storm's power and structure. At this intensity, the storm's rotating winds are often strong enough to begin forming a distinct eye, the calm center that is the hallmark of a mature hurricane. The potential for damage also escalates dramatically at this point. While a tropical storm can cause significant issues, a Category 1 hurricane's winds are capable of producing widespread damage to homes, trees, and power lines.

Once a storm crosses this 74 mph threshold, it has officially entered the first of five hurricane categories. The scale continues upward, culminating in a devastating Category 5 storm, which features catastrophic sustained winds of 157 mph or higher. While they are called hurricanes in the Atlantic, these same powerful weather systems are known as typhoons in the Northwest Pacific and cyclones in the South Pacific and Indian Oceans.