Day Length Guide

Longest and Shortest Days of the Year: What Are Solstice Dates?

The longest and shortest days of the year are connected with the solstices. A solstice happens twice a year and marks an important turning point in the daylight cycle.

What is the summer solstice?

The summer solstice is the day with the longest period of daylight. In the Northern Hemisphere, it usually happens around June 20 or June 21. In the Southern Hemisphere, it usually happens around December 21 or December 22.

On this day, the Sun reaches its highest apparent position in the sky for that hemisphere, and daylight lasts longer than on any other day of the year.

What is the winter solstice?

The winter solstice is the opposite. It is the day with the shortest period of daylight. In the Northern Hemisphere, it usually occurs around December 21 or December 22. In the Southern Hemisphere, it usually occurs around June 20 or June 21.

On this day, the Sun stays above the horizon for the shortest amount of time.

Why the Sun seems to pause

The word “solstice” comes from the idea that the Sun appears to pause in its yearly movement. Around the solstice, sunrise and sunset times change very slowly for several days.

After the summer solstice, days slowly begin to get shorter. After the winter solstice, days slowly begin to get longer.

Solstices at high latitudes

Solstice effects are strongest at high latitudes. Near the Arctic Circle, summer can bring extremely long days, and in some places the Sun may not set at all. This is known as the midnight sun.

In winter, the opposite can happen: some areas may have very little daylight or even polar night. Near the equator, solstices are less dramatic because day length stays close to 12 hours throughout the year.

How solstice dates help with planning

Solstice dates are useful for travel, photography, astronomy and outdoor planning. If you want long daylight hours for sightseeing, hiking or evening walks, traveling near the summer solstice can be a good choice.

If you want to experience short winter days, low sunlight or polar conditions, the winter solstice period may be more interesting. The solstices remind us that daylight is not fixed. It follows a yearly cycle that depends on Earth’s tilt, orbit and your location on the planet.