It’s the tilt

Earth spins on an axis that leans by about 23.4°, and it keeps leaning the same way all the way around its orbit. So for half the year the northern half of the planet leans towards the Sun, and for the other half it leans away.

When your half leans towards the Sun, sunlight comes down steeply. The same beam lands on a smaller patch of ground, so every square metre gets more energy. When your half leans away, the light arrives at a slant and, as NASA puts it, it “gets spread over larger and larger surface areas”. Same Sun, thinner sunshine. That’s winter.

Try it with a torch: shine it straight down at a table, then tilt it. The tilted spot is bigger and dimmer.

The giveaway: we’re closest to the Sun in January

Earth’s orbit isn’t a perfect circle. At its closest point it is about 91.4 million miles from the Sun, and at its farthest about 94.5 million miles, according to NASA Space Place. The closest point comes in early January. In 2026 it fell on 3 January, and the farthest on 6 July (U.S. Naval Observatory).

So Europe and North America have their winter while Earth is nearest the Sun. And when it’s summer in Berlin, it’s winter in Sydney. If distance ran the seasons, the whole planet would have summer at the same time.

Does distance do anything at all?

A little. From NASA’s figures, Earth is about 3% farther away in July than in January. Sunlight weakens with the square of the distance, so the whole planet gets roughly 7% more sunlight in early January than in early July. That’s real, but it’s the same for both hemispheres, and it is outweighed by the tilt. NASA’s verdict: the change in distance “does not make much difference to our weather.”

Why the myth feels so right

Closer to a fire, warmer. It’s a perfectly sensible guess. In a 2012 survey in Belgium, half of the respondents blamed a shorter Earth–Sun distance. The authors noticed something lovely: many of the same people correctly said that Australia has its seasons the other way round. Knowing a fact and connecting it to the cause are two different things, and that’s true for all of us.

Want the longer version, with solstices, equinoxes and why the hottest days come weeks after the longest one? Read why we have seasons.