Why Earth is hot despite being far from Sun

• Earth reaches aphelion, its farthest point from the Sun, on 6 July 2026
• Axial tilt, not distance, is the primary cause of seasonal changes
• Northern Hemisphere summers are slightly cooler due to this distance

As the summer heat beats down, here’s a cosmic riddle: on July 6, 2026, Earth reaches aphelion, its farthest point from the Sun all year. How can we be millions of kilometres farther from our heat source and still be sweating? It’s a paradox that puzzles many.

The Common Misconception

It’s an intuitive thought: closer to the Sun means hotter, and farther means colder. This leads many to believe our seasons are caused by Earth’s changing distance from the Sun as it follows its not-quite-circular, elliptical orbit. It makes sense, but it’s incorrect. In fact, for the Northern Hemisphere, our planet is closest to the Sun (a point called perihelion) in the cold of January and farthest away (aphelion) in the heat of July. This backward-seeming timing is the clearest sign that distance isn't the main story when it comes to our seasons.

The Real Reason: It's All in the Tilt

The true cause of the seasons is the tilt of Earth's axis. Our planet doesn't spin straight up and down relative to its orbit; it’s tilted by about 23.5 degrees. This tilt means that for part of the year, the Northern Hemisphere is angled toward the Sun, and for the other part, it’s angled away. When our hemisphere is tilted toward the Sun, as it is around June and July, we receive the Sun’s rays more directly. Think of a flashlight shining straight down on a surface—the light is concentrated and intense. That's summer. When we're tilted away, the sunlight strikes us at an oblique angle, spreading the energy over a larger area and feeling weaker, which brings winter.

More Daylight, More Heat

The axial tilt has a second important effect: it changes the length of our days. During summer in the Northern Hemisphere, our tilt toward the Sun means we spend more hours in daylight. Longer days mean more time for the Sun to heat the land, air, and water. The combination of more direct sunlight and longer days is what truly drives summer temperatures up, creating the heat we feel. The Southern Hemisphere, tilted away from the Sun at this time, experiences the opposite: shorter days, less direct sunlight, and winter.

So Does Distance Matter at All?

While tilt is the primary driver, the changing distance does have a subtle effect. At aphelion in early July, Earth is about 152.1 million kilometres from the Sun, compared to about 147.1 million kilometres at perihelion in January. That difference of five million kilometres means Earth receives about 7% less solar energy at its farthest point. However, this minor reduction is completely overshadowed by the powerful effect of our axial tilt. Interestingly, according to Kepler's laws of planetary motion, Earth moves slower in its orbit when it is farther from the Sun. This means that during aphelion, our planet lingers a bit longer in this part of its orbit, making summer the longest season in the Northern Hemisphere by nearly five days.

A Tale of Two Hemispheres

The timing of aphelion and perihelion does have a moderating effect on the planet's climate overall. Because the Northern Hemisphere has its summer when Earth is farthest from the Sun, our summers are slightly cooler than they would be otherwise. Conversely, our winters occur when Earth is closest, making them a bit milder. The Southern Hemisphere experiences the opposite. Its summer coincides with perihelion (closest approach), giving it more intense solar radiation, and its winter aligns with aphelion (farthest distance), making its winters slightly colder. However, the vast amount of ocean in the Southern Hemisphere helps absorb that extra summer heat, balancing the effect.