Under the meteorological definition, spring is based on temperature cycles rather than positions of the sun. In the Northern Hemisphere, meteorological spring spans the entire months of March, April, and May. In the Southern Hemisphere, it encompasses September, October, and November. This definition provides fixed dates that align more closely with civil calendars and actual weather trends. Phenological Indicators of Spring
Migratory birds return, insects emerge, and mammals begin foraging and breeding. Key Characteristics of the Spring Season spring definition season
By using fixed dates, meteorologists can easily compare climate data and weather patterns from year to year. It also aligns more closely with the actual warming of temperatures, as the atmosphere and oceans take time to heat up after the winter solstice. The Phenological (Ecological) Definition Under the meteorological definition, spring is based on
: Defined by the Earth's position relative to the sun. It begins on the vernal equinox —typically March 20 or 21 in the Northern Hemisphere and September 22 or 23 in the Southern Hemisphere—when day and night are approximately equal in length. This definition provides fixed dates that align more
: Trees sprout new leaves, flowers begin to bloom, and many animals begin their breeding seasons.
: The Earth's axis tilts toward the sun, causing the hemisphere to warm and snow to melt.
: Culturally, spring is widely viewed as a symbol of rejuvenation, renewal, and hope. It is often associated with themes of birth and fresh starts. Climatic Variability