The clocks have already been set back, but the days will get even shorter: on this date, the sun will set at 5:18 p.m. in Lisbon

The clocks have already been set back: in the early morning of October 25, at 2:00 a.m., they were set back to 1:00 a.m., and we gained an extra hour of sleep. But if you think the days are short and you don’t like it, get ready, because they’re going to get even shorter: the shortest day of the year in Lisbon is Monday, December 21, with the arrival of the winter solstice.

However, this doesn’t mean that December 21 is the day the sun sets earliest in the capital. In fact, that happens around December 6 and 7, at approximately 5:14 p.m., two weeks before the solstice. It seems like a mistake, but it isn’t. The shortest day of the year doesn’t coincide with the earliest sunset, and Lisbon clearly illustrates this difference.

The winter solstice marks the beginning of astronomical winter and the day with the fewest hours of daylight. In Lisbon, the sun rises at 7:50 a.m. and sets at 5:18 p.m., resulting in only 9 hours and 27 minutes of daylight. At solar noon, the sun does not rise higher than 27.9° above the horizon, which is why shadows lengthen and the light appears more diffuse.

The difference compared to summer is significant. On the summer solstice, Lisbon has about 14 hours and 53 minutes of daylight—more than five hours and 25 minutes longer than now. On that day, the sun reaches an altitude of 74.7°.

The explanation lies in how the sun’s cycle varies relative to clock time throughout the year. Starting in early December, the sun begins to set later, but it also continues to rise later. Until the solstice, the loss of light in the morning outweighs the gain in the late afternoon, so the days are still getting shorter.

For those leaving work in the late afternoon, this good news arrives just before Christmas. As for sunrise, it’s still late, and the dark mornings will continue.

The winter of 2026–2027 lasts about 89 days. It ends with the March equinox, on March 20, 2027, at 8:24 p.m. After the solstice, the days begin to get longer, albeit slowly. In 2027, the December solstice will fall on the 22nd, at 2:42 a.m.