Autumn Arrives in Ireland as Equinox Marks Equal Day and Night

Ireland welcomed the official start of autumn yesterday evening, as the autumnal equinox brought an even balance between day and night across the island.

The equinox, which occurred yesterday evening, marks the point in the year when the sun crosses the celestial equator, resulting in roughly equal hours of daylight and darkness. Across Ireland, this astronomical milestone signals the transition from the long, warm days of summer to the cooler, shorter days of autumn.

Adding a striking visual perspective, EUMETSAT’s Meteosat Third Generation (MTG) satellite captured stunning real-time imagery of the equinox over the Atlantic Ocean.

Meteorological Implications

Meteorologically, the equinox signifies a transition from the warmer, drier conditions of summer to the cooler, wetter patterns characteristic of autumn. In Ireland, this shift is often accompanied by increased rainfall and a drop in temperatures.

The change in daylight hours influences weather systems, leading to more frequent Atlantic depressions and unsettled weather conditions. This period also marks the beginning of meteorological autumn, which spans the months of September, October, and November.

The ongoing crisp and bright autumnal conditions will likely persist through Friday, ahead of a band of rainfall crossing the country on Friday evening. Conditions will improve through the second half of Saturday and Sunday.

Astronomical Significance

Astronomically, the equinox occurs when the Earth’s axis is tilted neither toward nor away from the Sun, resulting in the Sun being positioned directly above the equator at noon. This alignment causes the Sun to rise due east and set due west for observers in Ireland. The equinox also signals the end of astronomical summer and the commencement of astronomical autumn, which lasts until the winter solstice in December.

Cultural and Folkloric Traditions

In Irish folklore, the equinox has long been associated with harvest time and seasonal rituals. Traditions such as the Lughnasadh festival, held in early August, celebrate the gathering of crops and the abundance of the land. Folktales suggest that the balance between day and night during the equinox was a time when the veil between worlds was thin, and ceremonies performed at this time were believed to bring protection and prosperity for the coming winter.