Summer solstice marks the first day of the astronomical summer

Saturday is set to be the longest day of the year, officially marking the arrival of astronomical summer.

Known as the summer solstice, June 21st brings us the most daylight hours of 2025, with the sun rising early and setting late across the country. In Dublin, for example, daylight will stretch to around 17 hours and 15 minutes, giving us plenty of time to enjoy the outdoors.

The solstice occurs when the Earth’s Northern Hemisphere tilts closest to the sun, bathing Ireland in maximum sunlight. This moment signals the official start of astronomical summer, the season defined by Earth’s position in space rather than just weather or calendar dates.

From Saturday onward, while the days remain long for a few weeks, daylight hours will slowly begin to shorten again as we head towards autumn.

So set your alarm early or enjoy a long evening — the longest day of the year is here, and the astronomical summer has officially begun!