Why does daylight change through the year?

Earth's axis is tilted about 23.4 degrees relative to its orbit around the Sun. As Earth moves through its yearly orbit, that tilt means the Northern and Southern Hemispheres take turns leaning toward the Sun. When your hemisphere leans toward the Sun, days are longer and the Sun rises higher in the sky; when it leans away, days are shorter. The effect is strongest near the poles and nearly absent at the equator.

What is the longest day of the year?

The longest day is the summer solstice, which falls on or around June 20-21 in the Northern Hemisphere and December 21-22 in the Southern Hemisphere. On that date, the Sun reaches its highest noon altitude for the year and daylight lasts longest. Exactly how long depends on latitude: at 40 degrees north (roughly New York, Madrid, or Beijing) the longest day is about 15 hours, while at the Arctic Circle the Sun never sets.

How do polar regions get 24 hours of daylight?

North of the Arctic Circle (about 66.5 degrees north) and south of the Antarctic Circle, Earth's axial tilt places the Sun above the horizon for the full 24 hours around the summer solstice, giving the midnight sun. The same geometry produces polar night in winter, when the Sun never rises. The closer you get to the poles, the longer these periods last — at the pole itself, there is roughly six months of continuous day followed by six months of continuous night.

Daylight tool

Sunrise & sunset year-round.

Daylight curves for any city across the full year.

Sunrise / Sunset Wave

Year-long daylight curve. Shows how dramatic high-latitude summers are.

Sunrise

Sunset

Night

Today in sample city

Sunrise, sunset, golden hour, civil twilight

24h strip

Sunrise

05:55

Sunset

20:07

Golden hour (AM)

06:02 – 06:58

Civil twilight

05:22 / 20:40

Terminator

Day / night boundary across the globe right now

WestSubsolar pointEast

Globe view

Where the sun is right now

Day / Night Terminator

Shadow marks where it is currently night. Drag to spin the globe; scrub to fast-forward ±12 hours.

Sun position

Directly overhead at:

12.1°, 4.7°

Viewing: Wed, 22 Apr 2026 11:41:09 GMT

Time scrubber (±12h)

−12h+0h+12h

Reading the curve

How to read the daylight curve

The key thing to look for is not just the earliest sunrise or latest sunset, but how quickly the shape changes as you move through the year. Mid-latitude cities have a pronounced wave where day length grows and shrinks quickly in spring and autumn. Equatorial cities stay much flatter, and polar regions become extreme enough to produce midnight sun or polar night.

That makes this page useful for much more than curiosity. Travel planning, photography, outdoor events, agriculture, fasting schedules, and solar-energy checks all depend on how the daylight curve behaves across the full year rather than on one sunrise and one sunset today.

Latitude

Why latitude matters more than timezone here

A timezone tells you what the clock says, but latitude tells you what the sun is doing. Two cities can share the same civil time and still have dramatically different daylight patterns if one sits much farther north or south. That is why sunrise and sunset pages should always explain the seasonal geometry, not just print a pair of times.

In practical terms, this tool pairs especially well with city pages, holiday planning, and the jet-lag tool. People often discover that the hard part of a trip is not only the timezone shift, but also the way daylight length changes at the destination.

Questions

Frequently asked questions

Why does daylight change through the year?: Earth's axis is tilted about 23.4 degrees relative to its orbit around the Sun. As Earth moves through its yearly orbit, that tilt means the Northern and Southern Hemispheres take turns leaning toward the Sun. When your hemisphere leans toward the Sun, days are longer and the Sun rises higher in the sky; when it leans away, days are shorter. The effect is strongest near the poles and nearly absent at the equator.
What is the longest day of the year?: The longest day is the summer solstice, which falls on or around June 20-21 in the Northern Hemisphere and December 21-22 in the Southern Hemisphere. On that date, the Sun reaches its highest noon altitude for the year and daylight lasts longest. Exactly how long depends on latitude: at 40 degrees north (roughly New York, Madrid, or Beijing) the longest day is about 15 hours, while at the Arctic Circle the Sun never sets.
How do polar regions get 24 hours of daylight?: North of the Arctic Circle (about 66.5 degrees north) and south of the Antarctic Circle, Earth's axial tilt places the Sun above the horizon for the full 24 hours around the summer solstice, giving the midnight sun. The same geometry produces polar night in winter, when the Sun never rises. The closer you get to the poles, the longer these periods last — at the pole itself, there is roughly six months of continuous day followed by six months of continuous night.