What range of wind speeds defines a tropical depression?

A tropical depression is defined by wind speeds ranging from 0 to 38 miles per hour. This classification indicates a system with organized convection and defined circulation that does not yet reach the intensity of a tropical storm. The upper limit of 38 mph marks the point where the system can be designated as a tropical storm, which involves higher wind speeds and more significant weather impacts. Understanding this classification is crucial for meteorologists when monitoring and predicting tropical systems as they develop, allowing for timely alerts and community preparedness.