solstice

As happens with the term "equinox," its use is relatively common in Meteorology and Climatology texts. The word comes from the Latin solstitium, which literally means "sun stands still," as it marks each of the two moments of the year when the sun, on its path across the celestial vault, reaches its greatest and smallest height relative to the horizon in each of the Earth's hemispheres and halts its upward or downward progression. In the northern hemisphere, the winter solstice usually falls on December 21 or 22, corresponds to the longest night of the year, and marks the beginning of astronomical winter, while the summer solstice occurs almost always on June 20 or 21, is the day with the most hours of sunshine of the year, and marks the beginning of astronomical summer. The correspondence between each solstice and its date of occurrence is reversed in the southern hemisphere (the winter one falls in June and the summer one in December).