In Ireland and parts of the British Isles, traditional seasons follow the Celtic festivals. They believe the season starts on the cross-quarter days (midpoints between solstices/equinoxes).

The exact timing of the four seasons depends entirely on whether you are measuring them through the lens of astronomy or meteorology. While most people mark the changing seasons by the dates on a calendar, scientists use two distinct systems to track the year.

Begins at the Summer Solstice (June 20–22) and ends at the Autumnal Equinox. The solstice marks the longest day of light in the year. Meteorological: Begins on June 1 and ends on August 31 .

Scientists, meteorologists, and calendar makers divide the year using two main frameworks. Both are accurate, but they serve completely different purposes. 1. Astronomical Seasons (Based on the Earth and Sun)

As if two systems weren't enough, many cultures and industries define seasons by local ecology or tradition. These are less precise but often more meaningful.

Most people are familiar with the astronomical seasons, which are based on the Earth's position relative to the sun. These start and end on specific "turning points":