As the long winter months fade away, the days start to get longer, bringing a welcome increase in daylight approximately four extra minutes each day. The sun’s warmth begins to return, making many people wonder if spring is just around the corner. However, the actual start of spring depends on the method used to define it. There are three main ways to determine the beginning of spring: meteorological, astronomical, and phenological.
Meteorologists define the start of spring based on calendar months. According to this system, spring officially begins on March 1st and lasts until May 31st. This grouping allows weather forecasters to analyze seasonal patterns and compare climate data consistently.
Using a fixed date for seasonal transitions simplifies weather records and helps climatologists track long-term trends. Unlike astronomical spring, which varies slightly each year, meteorological spring follows a standard timeline, making it a practical choice for weather studies and forecasts.
The more traditional way to mark the start of spring is through astronomical spring, which depends on Earth’s position relative to the Sun. This method defines spring’s arrival with the spring equinox, the moment when day and night are nearly equal in length. In 2025, this event will take place on March 20th.
The equinox occurs because of Earth’s axial tilt and orbit around the Sun. As the Sun crosses the celestial equator from the Southern Hemisphere to the Northern Hemisphere, daylight hours become longer. The term “equinox” comes from Latin, where equi means “equal” and nox means “night.”
Astronomical spring continues until the summer solstice, which in 2025 will occur on June 21st. From that point, the days will reach their longest length of the year, marking the beginning of summer.
Beyond calendar-based definitions, some people observe seasonal changes through phenology, which studies the timing of natural events like plant blooming and animal behavior. Phenological spring is not tied to a fixed date but is based on environmental cues such as temperature shifts and daylight changes.
Signs of phenological spring include the appearance of frogspawn, which may occur as early as February, and bluebells, which often bloom in April. However, climate change is influencing these patterns. Studies, including those by the Woodland Trust, show that many plant and animal species are emerging earlier than they did in previous decades.
As spring approaches, many countries adjust their clocks for Daylight Saving Time (DST) to make better use of natural daylight. In 2025, clocks in the UK will go forward by one hour at 1:00 AM on Sunday, March 30th. This shift means losing an hour of sleep but gaining longer evenings.
In the United States, the transition happens earlier, on Sunday, March 9th, 2025, at 2:00 AM local time. Not all regions observe DST, so it’s always good to check local regulations.
Spring’s arrival depends on how you define it meteorological spring begins on March 1st, astronomical spring starts with the equinox on March 20th, and phenological spring is marked by natural changes like blooming flowers. Whichever method you follow, one thing is certain: longer, brighter days are on their way, bringing the promise of renewal and warmth.
