Meteorological seasons are defined by the annual temperature cycle and are based on the Gregorian calendar. They divide the year into four distinct seasons: spring, summer, autumn, and winter. Each season lasts for three months, making it easier for meteorologists to analyze and compare climate data. In the Northern Hemisphere, spring runs from March 1 to May 31, summer from June 1 to August 31, autumn from September 1 to November 30, and winter from December 1 to February 28 (or 29 in a leap year). The Southern Hemisphere has the same seasonal structure but experiences opposite seasons.