Dates - Four Seasons

These dates were more closely aligned with agricultural cycles. For an ancient farmer, "spring" began when the lambs were born and the ground thawed, not when the Sun crossed a celestial equator. Remnants of these traditions persist in modern holidays such as Groundhog Day (Imbolc), May Day (Beltane), and Halloween (Samhain).

In the 21st century, the stability of seasonal dates faces a new challenge: anthropogenic climate change. While the astronomical dates of the solstices and equinoxes remain constant, the "phenological" seasons are shifting.

Before the advent of modern meteorology, the dates of the seasons were inextricably linked to phenology—the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life.

Sunday, 21 June 2026. The longest day of the year and the official kickoff to beach season. four seasons dates

When the Northern Hemisphere is tilted toward the Sun (experiencing the June solstice), the Southern Hemisphere is tilted away, experiencing winter. Consequently, the seasonal dates are flipped:

Friday, 20 March 2026. This marks the moment day and night are nearly equal in length.

Meteorologists and climatologists utilize a different system designed to simplify the statistical tracking of weather data. The astronomical seasons vary in length between 89 and 93 days, making the calculation of seasonal statistics cumbersome. Furthermore, the thermal lag—the delay between maximum solar insolation and maximum atmospheric heating—means that the hottest days of the year usually occur weeks after the summer solstice. These dates were more closely aligned with agricultural

Global warming has led to an expansion of the thermal summer season. Studies indicate that summers are lengthening while winters are shrinking in duration. In many temperate zones, the onset of spring-like temperatures is occurring weeks earlier than the historical average. This creates a dissonance between the calendar and the environment; the astronomical calendar states it is still winter (March 1st), but the flowering trees have already bloomed.

The Dynamics of the Calendar: A Comprehensive Analysis of the Four Seasons, Their Dates, Astronomical Origins, and Cultural Significance

If your interest is more mid-century pop, you’re likely thinking of the legendary band behind hits like "Sherry" and "December, 1963 (Oh, What a Night)." In the 21st century, the stability of seasonal

To address this, meteorological seasons are based on the annual temperature cycle and are divided into four periods of three full months each:

The traditional East Asian calendar divides the year into twenty-four solar terms. While the solstices and equinoxes are central, the seasons are further subdivided to guide agricultural activity. "Spring" (Li Chun) typically begins around February 4th, aligning more closely with the Celtic cross-quarter day than the March equinox. This highlights that the concept of seasonal dates has always been fluid, tailored to the specific climatic needs of a region.