Earth Reaches Furthest Point From Sun
Aphelion occurs July 3, but don’t blame it for summer.
On July 3, 2025, at 3:54 pm ET, Earth will reach aphelion, its farthest distance from the Sun this year. Although this event might seem related to the seasons, it’s actually a coincidence, driven by Earth’s axial tilt.
Aphelion Explained
Aphelion refers to the point in Earth’s orbit when it is farthest from the Sun. Conversely, perihelion is when Earth is closest, occurring around January 3, 2026. Earth’s orbit isn’t a perfect circle but an ellipse, causing variations in our distance from the Sun.
At aphelion, the distance between Earth and the Sun will be 152,087,738 kilometers (94,502,939 miles). During perihelion, Earth is about 5.1 million kilometers (3.2 million miles) closer, resulting in approximately 6.8 percent more solar radiation reaching the planet in January.
Seasons Are About Tilt, Not Distance
The timing of aphelion and perihelion near the solstices is coincidental and unrelated to the seasons. The seasons are determined by the tilt of the Earth’s axis.
Currently, the Northern Hemisphere is tilted towards the Sun, resulting in summer, while the Southern Hemisphere experiences winter. In six months, the situation reverses.
Orbital Shifts Over Time
Aphelion and perihelion dates shift over time. Specifically, there’s a shift of about one day every 58 years. Leap years introduce smaller variations annually, leading to day-to-day changes.
In the late 19th century, New Year’s Day coincided with perihelion, while in the mid-1200s, the solstices aligned with these special days.
Gravitational Influence
The subtle gravitational forces exerted by **Jupiter** and **Saturn** influence the Earth’s orbit. Over hundreds of thousands of years, our planet’s orbit fluctuates from slightly elliptical to nearly circular, a phenomenon known as one of the Milankovitch cycles.
Despite changes in the shape of Earth’s orbit, the length of the year remains constant due to gravitational laws. A more elliptical orbit simply means Earth is closer to the Sun during spring and autumn compared to its current position. NASA says that these Milankovitch cycles affect the timing of the seasons and can impact long-term climate change (NASA Earth Observatory).
Seasonal Lengths Affected
While the orbital shape doesn’t change the year’s duration, it does affect the length of the seasons. Astronomical seasons are defined by Earth’s position in its orbit. A more circular orbit results in more uniform season lengths. Currently, summer in the Northern Hemisphere is 4.66 days longer than winter, and spring is 2.9 days longer than autumn.
