Perihelion is an astronomical occurrence that happens around two weeks from the December Solstice. Even though it is winter in the Northern Hemisphere during this period, Earth reaches the closest point of over 91 million miles to the sun on this day. Perihelion does not directly affect Earth’s temperature; it does not make us feel any warmer, nor does it provide respite from the chilling temperature. However, it does indirectly affect seasons because Earth’s orbital speed is at its maximum at perihelion. On this day, the sun appears the largest in the sky for the entire year, gradually growing smaller through the remainder of the year.
In 1246, Perihelion Day was on the December Solstice. Every 58 years since then, the date has changed by a day. Perihelion Day varies each year due to precession and orbital factors that follow specific cyclical patterns known as the Milankovitch cycles. Another cause is the moon’s presence, which can make the date vary by up to two days from one year to another. While the Earth-Moon barycenter moves on a stable orbit around the sun, Earth’s center, which is around 2,900 mi from the barycenter, can shift in any direction from it, thus affecting the actual time of the perihelion.
Under The Harvest Moon 