The document discusses the Mexican Monsoon Time Scale, which is a chronological sequence of events arranged in a scale to study the past, present, and future movements of the Mexican Monsoon and its relationship to weather patterns. The scale is prepared with 365 horizontal days to track weather events each year. Studying the scale over many years can reveal patterns in monsoon rainfall, droughts, floods, and other weather phenomena in northwestern Mexico and the southwestern US. The document provides examples of how similar time scales have been used to study the Indian Monsoon and its impacts.