Solstice Calendar 2025. When is the winter solstice/first day of winter 2025? The first day of winter is marked by the winter solstice, which occurs when the earth’s axis tilts farthest from the sun.
In 2025, the solstice moment will fall at 2:42 utc on june 21 (9:42 p.m. 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 located at the maximum distance north of the celestial equator.