First Day Of Summer 20254 2025 Date. This is the longest day of the year and marks the start of summer in. The summer solstice is the day with the most hours of sunlight during the whole year.

Summer solstice 2025 (beginning of astronomical summer) on the day of the summer (june) solstice, the solar disk, moving along the ecliptic, will fall into its northernmost point and will be. Known in icelandic as ‘sumardagurinn fyrsti’, the first thursday after april 18th is an icelandic public holiday that.