If you are trying to explain to someone about why summer days are longer than winter days, you might say something like the followiung. At the bottom is a link to a daylight hours chart at no cost until May 1, 2026.
After the first day of summer—the summer solstice—the days begin to get shorter. The first day of winter has the smallest number of daylight hours. The sun sets so early that you find yourself wandering around your home at what feels like midnight, but is technically late afternoon.
The important thing to remember is that the number of hours in a day never changes—there are always about 24—yet somehow in winter there are only six usable ones, three of which are spent looking for your other glove.
We know that Earth spins, causing the sun to rise and set. But why does the sun appear to rise and set at different times throughout the year?
Let’s build a model.
- Place a ball on the floor to represent the Sun.
- Place another ball a few feet away to represent Earth.
- Mark the top and bottom of the Earth ball with small pieces of tape to show the North and South Poles.
- How would you move the Earth to model day and night? (You would spin it slowly.)
- Spin the “Earth” to model day and night. While spinning it, carefully walk it in a circle around the Sun to model Earth’s yearly orbit.
So far, this model explains:
- Why we have day and night.
- Why a year takes one trip around the Sun.
But here’s the big question:
If the Earth stays straight up and down like this, would the length of daylight ever change? (No.)
So what are we missing?
Try this:
Tilt the Earth slightly (about 23.5°). Keep that tilt pointing in the same direction as you walk it around the Sun.
This is a common misunderstanding. Many people think summer happens because Earth is closer to the Sun. But Earth’s orbit is nearly circular, and in fact, Earth is slightly closer to the Sun during Northern Hemisphere winter.
So, in two words, what really causes summer?
It's the earth's tilt.
Earth’s axis is tilted 23.5 degrees. As Earth orbits the Sun, one side of the earth (hemisphere) tilts toward the Sun for part of the year. When that happens:
- The sun rises earlier.
- The sun sets later.
- The sun follows a higher, longer path across the sky.
That hemisphere stays in sunlight longer each day.
- The sun rises later.
- The sun sets earlier.
- The sun follows a lower, shorter path across the sky.
The amount of daylight changes not because of distance, but because of Earth’s tilt.
From now until May 1, 2026, use this link to get a free daylight hours chart: Open in New Tab