Earth is today at aphelion, the point in its orbit at which it is farthest from the sun. That means less radiation from the sun, which will look its smallest in the sky in 2025. Meanwhile, states in the Midwest are facing high temperatures as summer’s first heat wave hits. How can that make sense? Here's what you need to know about Earth's orbit of the sun and how it does — and doesn't — affect seasons.

Earth orbits the sun in a slight ellipse — an egg shape. There's a point when it's farthest from the sun (aphelion) and when it's closest to the sun (perihelion).

At 3:54 p.m. EDT on Thursday, July 3, our planet will reach aphelion. It will be 94.5 million miles (152 million kilometers) from the sun. Six months ago, on Jan. 4 — aphelion — that gap was 3.4% smaller, at 91.5 million miles (147 million kilometers) from the sun.

On Jan. 4, Earth received its maximum radiation from the sun, which was at its largest in the sky for 2025. The difference isn't huge — the sun today appears to be a mere arcminute (1/60th of a degree) smaller than at its perihelion.

The word aphelion comes from the Greek words apo (meaning away) and helios (meaning sun).

Although it may seem counterintuitive for where you live to be suffering a heatwave while the Earth is farthest from the sun, remember that the Earth is not only a globe, but it also rotates on a tilted axis.

Its 23.4-degree tilt determines the seasons by changing how different parts of the planet receive different amounts of sunlight throughout one orbit of the sun.

The Northern Hemisphere is currently titled towards the sun, so it gets more (and more intense) sunlight for longer than the Southern Hemisphere, which is now tilted away from the sun and has shorter, colder days.

Not that aphelion has zero effect on the seasons. Planets move faster at perihelion and slower at aphelion, according to NASA. Since the June solstice occurs close to aphelion, summer in the Northern Hemisphere lasts a few days longer than summer in the Southern Hemisphere.

The difference is about four days, although this year's Northern Hemisphere summer is 15 minutes shorter than in 2024 — thanks to the gravitational influence of the sun, the moon, and Jupiter, causing our orbital path to change ever so slightly.

Wishing you clear skies and wide eyes.