When Earth reaches perihelion and aphelion
Earth does not travel around the Sun in a perfect circle. Its orbit is slightly elliptical, so the Earth-Sun distance changes through the year. Perihelion is the moment when Earth is closest to the Sun, while aphelion is the moment when Earth is farthest away. The tool above uses the U.S. Naval Observatory Earth’s Seasons and Apsides service to list those two orbital milestones for the selected year. The same official dataset also contains the equinoxes and solstices, allowing the orbital-distance cycle and the seasonal cycle to be compared without confusing them.
Perihelion currently occurs in early January and aphelion in early July, but the exact date and time vary from year to year. This surprises many people in the Northern Hemisphere because Earth is actually closest to the Sun during northern winter and farthest during northern summer. That observation demonstrates an important point: the seasons are not caused primarily by the changing Earth-Sun distance. They are caused by Earth’s axial tilt, which changes the angle of sunlight and the length of daylight in each hemisphere.
Why seasons are caused by tilt, not distance
Earth’s axis is tilted by about 23.4 degrees relative to the plane of its orbit. Around the June solstice, the Northern Hemisphere is tilted toward the Sun and receives longer days and a higher midday Sun, while the Southern Hemisphere is tilted away. Around the December solstice the geometry reverses. If distance were the main cause of the seasons, both hemispheres would experience summer and winter at the same time, which they clearly do not. Use the Equinox & Solstice Dates page to compare the seasonal milestones directly with perihelion and aphelion.
The difference between perihelion and aphelion distance is large enough to measure but small compared with the total Earth-Sun distance. Earth’s average distance from the Sun defines one astronomical unit, approximately 149.6 million kilometres. Because the orbit has low eccentricity, the distance varies by only a few percent around that mean. Solar radiation at the top of Earth’s atmosphere is therefore somewhat stronger near perihelion than near aphelion, but axial tilt still dominates the familiar seasonal temperature pattern at the surface.
Why the apsides move over long periods
The orientation and shape of Earth’s orbit are not perfectly fixed. Gravitational interactions with other planets slowly change the orbit, while the direction of Earth’s rotational axis also precesses. Over very long timescales these cycles change the relationship between perihelion, aphelion and the seasons. The current pattern, with perihelion in early January, is therefore not a permanent feature of Earth’s climate system. Such long-term orbital variations are part of the broader family of Milankovitch cycles used in paleoclimate research.
For present-day observing, the immediate practical effect is smaller. The changing Earth-Sun distance slightly alters the Sun’s apparent angular size and the amount of solar energy received, but it does not noticeably change where you should look for the Sun on a normal day. For local geometry, use Sun Position Today, and for daylight duration use the Day Length Calculator.
Authoritative seasons and apsides data
The U.S. Naval Observatory Earth’s Seasons service provides equinox, solstice, perihelion and aphelion dates and times for years from 1700 through 2100. SpaceTracker.live uses that source through a same-origin cached request rather than maintaining a manually typed table. That approach reduces the chance that a future year is missing or copied incorrectly. The displayed times are Universal Time unless otherwise stated.
NASA’s Earth facts and science resources provide additional background on Earth’s orbit, rotation and physical properties. Combining those references with SpaceTracker’s Sun tools gives a practical progression: use this page for the annual orbital extremes, the equinox/solstice page for the seasonal markers, the sunrise calendar for local daylight changes and the astronomy calendar for other events occurring around the same dates.
How to use this calendar
Select a year and compare the perihelion and aphelion dates with the solstices. Then open Sunrise & Sunset Calendar for your location to see how daylight behaves through those months. The contrast makes the geometry easy to understand: Earth can be closest to the Sun while a northern location has short winter days, because the hemisphere is tilted away from the Sun. This connection between global orbit and local daylight is exactly why the apsides belong in the Calendar section rather than as an isolated fact page.
Perihelion and aphelion, 2026 to 2028
Earth is closest to the Sun (perihelion) in early January and farthest (aphelion) in early July. The distances are about 147.1 million km and 152.1 million km, a difference of just 3.3%. Because sunlight falls with the square of the distance, Earth receives roughly 6.9% more solar energy at perihelion than at aphelion. The table gives the dates calculated for the next three years.
| Year | Perihelion | Distance | Aphelion | Distance |
|---|---|---|---|---|
| 2026 | 3 Jan 2026, 17:00 UTC | 0.9833 AU (147.1 million km) | 6 Jul 2026, 18:00 UTC | 1.0167 AU (152.09 million km) |
| 2027 | 3 Jan 2027, 02:00 UTC | 0.9833 AU (147.1 million km) | 5 Jul 2027, 05:00 UTC | 1.0167 AU (152.1 million km) |
| 2028 | 5 Jan 2028, 13:00 UTC | 0.9833 AU (147.1 million km) | 3 Jul 2028, 23:00 UTC | 1.0167 AU (152.09 million km) |
Why the seasons are not caused by distance
If distance caused the seasons, the whole planet would be warmest in January. The Northern Hemisphere is in the middle of winter then, and the Southern Hemisphere is in summer. Seasons come from Earth's axial tilt of about 23.4°, which changes how directly sunlight strikes each hemisphere. Distance has only a small effect: it makes the Southern Hemisphere summers a little more intense and the northern ones a little milder.
Seasons are different lengths
Earth moves fastest at perihelion, so the seasons are not equal in length. Between the 2026 events, spring lasts about 92.7 days, summer 93.7 days, autumn 89.9 days and winter 89.0 days (northern hemisphere naming). Northern summer is the longest season, and northern winter the shortest. The Equinox and Solstice page lists the exact moments, and the Planet Distance from Sun page lets you compare the other planets.
Earth’s closest and farthest points from the Sun, 2027–2028
Earth’s orbit is a slightly flattened ellipse. The table gives the calculated instants (rounded to the hour, UTC) and the Earth–Sun distance at each.
| Event | Date (UTC) | Distance |
|---|---|---|
| Perihelion 2027 | 3 Jan 2027, about 02:00 | 147.10 million km (0.98333 AU) |
| Aphelion 2027 | 5 Jul 2027, about 05:00 | 152.10 million km (1.01673 AU) |
| Perihelion 2028 | 5 Jan 2028, about 13:00 | 147.10 million km (0.98330 AU) |
| Aphelion 2028 | 3 Jul 2028, about 23:00 | 152.09 million km (1.01668 AU) |
The difference is about 5 million km, or 3.3 per cent. Because sunlight intensity falls with the square of distance, Earth receives about 7 per cent more solar energy at perihelion than at aphelion, but this does not cause the seasons: they are caused by Earth’s 23.4° axial tilt, which is why the northern hemisphere is in winter when Earth is closest to the Sun.
Quick answers
Why is Earth closest to the Sun in January?
The date is a coincidence of the present orbit: perihelion drifts later by about one day every 58 years because of the slow rotation of Earth’s orbit.
Does the Sun look bigger at perihelion?
Yes, by about 3.4 per cent: roughly 32.5′ at perihelion versus 31.5′ at aphelion. The difference is too small to notice by eye, and solar eclipses are affected by the Moon’s distance far more.
Content last reviewed: 30 October 2026. Dates and times are UTC and were calculated for this page with the Astronomy Engine library; convert to your time zone before planning.