From an astronomical point of view, it starts getting lighter just after the winter solstice, when your hemisphere has its shortest day and longest night.

Key moment: winter solstice

  • The winter solstice is the point where your part of Earth is tilted furthest away from the Sun, giving the least daylight of the year.
  • After this moment, day length begins to increase again, so each day becomes a little lighter than the one before, even if it is hard to notice at first.

Rough dates (Northern Hemisphere)

  • In the Northern Hemisphere, the winter solstice falls around 20–23 December each year, most commonly on 21 December.
  • That means “it starts getting lighter” in late December, with the extra daylight becoming much more noticeable through January and February.

Why it doesn’t feel lighter right away

  • Around the solstice, sunrise can still get slightly later for a short while, even though sunset gets later, so mornings can feel dark for weeks.
  • This offset is caused by Earth’s tilted axis and its slightly elliptical orbit, which shift the times of sunrise and sunset relative to the actual shortest-day moment.

If you’re in the Southern Hemisphere

  • The pattern is the same but flipped: it starts getting lighter after the June solstice, which is the Southern Hemisphere’s winter solstice.
  • From then until the December solstice, days slowly grow longer and brighter.

Information gathered from public forums or data available on the internet and portrayed here.