A seasonal coefficient is a numerical value that represents the degree of variation in a particular phenomenon over the course of a year. It is used to measure the impact of seasonal changes on a specific variable, such as sales, weather patterns, or consumer behavior. This coefficient is calculated by comparing the average value of the variable during a specific season to the overall average for the entire year. A high seasonal coefficient indicates a significant seasonal effect, while a low coefficient suggests minimal seasonal influence. This term is commonly used in economics, meteorology, and marketing to better understand and predict seasonal trends.