Fact: The Northern Hemisphere is closer to the Sun in early January and farther in early July. Seasons are driven by Earth’s axial tilt, not our small change in distance from the Sun [1][2][3].
Sponsored Links
I like to collect facts that go against intuition. Here is a favorite. Every year Earth reaches perihelion, the closest point to the Sun, in early January. In 2025 it happened on January 4 at about 147 million km. About six months later we reach aphelion, the farthest point, which in 2025 falls on July 3 at about 152 million km [1][3][4].
That distance change is only about 3 percent, which is not enough to create seasons. The big driver is our planet’s 23.5 degree axial tilt. When the Northern Hemisphere tilts toward the Sun, sunlight arrives more directly and for more hours each day, so it is summer here. When it tilts away, sunlight is lower in the sky and days are shorter, so it is winter here. The Southern Hemisphere flips those seasons at the same time [1][2][5].If the distance change is small, why do some people expect the opposite? It is easy to assume that being closer means warmer. In reality the tilt controls the intensity and duration of sunlight. Distance adds a small effect only. You can also see a seasonal lag in many places. Temperatures often peak weeks after the June solstice, and the coldest days arrive after the December solstice, because land and oceans store and release heat over time [2].
One more neat point. Because Earth is slightly closer to the Sun in Northern winter, we also move a little faster in our orbit at that time. That makes Northern Hemisphere winter a bit shorter and Northern summer a bit longer compared to the Southern Hemisphere, which experiences the reverse pattern [3][6].
Do This
- Mark your calendar for perihelion in early January and aphelion in early July, then watch sunrise and sunset times change across the seasons [3][4].
- When someone says it is cold because we are far from the Sun, share the tilt explanation and the 3 percent distance change [1][2][5].
Bottom Line
We are closest to the Sun during Northern winter and farthest during Northern summer. The reason seasons feel so different is the tilt of Earth’s axis, not the small difference in distance [1][2][3].
