Meet Aphelion, Earth's Farthest Point
Every year in early July, the Earth reaches a point in its orbit called 'aphelion'. The name comes from the Greek words 'apo' (away) and 'helios' (sun). On this day, our planet is at its maximum distance from our star. In 2026, this occurs on July 6, when
Earth will be over 152 million kilometres away from the sun. That's about 5 million kilometres farther than it is at its closest point, 'perihelion', which happens in early January. It’s a common misconception to think this extra distance should make things cooler, but the reality of our seasons is governed by a much more powerful force.
The Real Reason for the Seasons: It's All in the Tilt
The primary driver of Earth's seasons is not our planet's slightly elliptical orbit, but its axial tilt. The Earth spins on an axis that is tilted at an angle of about 23.5 degrees. This tilt means that for half of the year, the Northern Hemisphere is angled more directly toward the sun, while the Southern Hemisphere is angled away, and vice versa for the other half. When a hemisphere is tilted towards the sun, the sun's rays hit it more directly, like a flashlight shining straight down. This concentrated energy, combined with longer daylight hours, results in the warmer temperatures of summer. This is why aphelion in early July coincides with summer in the Northern Hemisphere and winter in the Southern Hemisphere.
A Tale of Two Hemispheres
The fact that the two hemispheres experience opposite seasons at the same time is the clearest evidence that distance isn't the key factor. While people in India and the rest of the Northern Hemisphere are experiencing summer's peak, countries in the Southern Hemisphere, like Australia and Argentina, are in the middle of their winter. Their side of the planet is tilted away from the sun, receiving less direct solar energy. In fact, for those in the Southern Hemisphere, the timing makes perfect sense: the Earth is farthest from the sun during their winter. The seeming paradox of a hot aphelion is purely a Northern Hemisphere perspective.
So, Does the Distance Matter At All?
The varying distance from the sun does have a small effect, but it's not what you might expect. The total variation in solar energy Earth receives between its closest and farthest points is only about 7%. This minor difference is easily overshadowed by the massive impact of the axial tilt. Interestingly, the Earth as a whole is actually slightly warmer during aphelion (Northern Hemisphere summer) than during perihelion (Northern Hemisphere winter). This is because the Northern Hemisphere has significantly more landmass than the Southern Hemisphere, and land heats up more quickly and intensely than water. So, the vast continents of the north baking in their summer sun raise the planet's overall average temperature, even from 5 million kilometres farther away.
A Longer, Lazier Summer
There's one more subtle effect of our distant July stroll. According to Kepler's laws of planetary motion, a planet moves more slowly in its orbit when it is farther from the sun. Because Earth is at its farthest point during the Northern Hemisphere's summer, it is also moving at its slowest speed. This means that summer in the Northern Hemisphere is actually the longest season of the year, lasting nearly five days longer than our winter. Conversely, the Southern Hemisphere's summer is their shortest season, as the Earth speeds through its closest approach to the sun in January. It's a small but fascinating consequence of the same orbital mechanics that give us a hot day when we're furthest from our star.
