On Thursday, July 3, 2025, at 3:54 p.m. EDT, Earth reached aphelion—the point in its orbit where it is farthest from the sun. At this moment, our planet was approximately 94.5 million miles (152 million kilometers) away from the sun, about 3.4% farther than it was six months earlier at perihelion, when it was closest at 91.5 million miles (147 million kilometers). This astronomical event means the sun appears slightly smaller in the sky today, about one arcminute (1/60th of a degree) smaller than at perihelion.
But despite Earth being at its greatest distance from the sun, many regions across the United States are sweltering under a significant heat wave. From the middle-Atlantic coast stretching through the Greater Ohio Valley, Central Great Plains, Texas, Oklahoma, and down into the Desert Southwest, temperatures are soaring above 90 degrees Fahrenheit. Some desert areas in southwest Texas, southern and western Arizona, southern Nevada, and southeast California are even expected to reach or exceed 100 degrees, with certain spots nearing 110 degrees. Meanwhile, parts of California (except the Pacific Coast), Nevada, and much of the Pacific Northwest are also experiencing high temperatures.
This seeming contradiction—Earth being farthest from the sun while temperatures climb—can be explained by the planet’s axial tilt rather than its distance from the sun. Earth’s 23.4-degree tilt on its axis is the primary driver of seasons and temperature variations. Currently, the Northern Hemisphere is tilted toward the sun, receiving more direct sunlight for longer hours each day, which intensifies the heat despite the increased distance.
Kepler's laws of planetary motion tell us that Earth moves more slowly in its orbit when it is farther from the sun, and faster when it is closer. At aphelion, Earth travels at just under 18 miles per second (29 kilometers per second), compared to just over 19 miles per second at perihelion. This slower orbital speed near aphelion slightly lengthens the Northern Hemisphere’s summer by about four days compared to the Southern Hemisphere, because the June solstice occurs close to this farthest point from the sun.
Interestingly, despite the sun being about 3.28% dimmer at aphelion compared to perihelion, this difference has only a minor effect on seasonal temperatures. The sun appears roughly 6.55% dimmer now than it did in January, but that variation is overshadowed by the effects of Earth’s tilt, which changes the angle and duration of sunlight reaching different parts of the globe.
At New York’s latitude, for example, the sun’s rays at the summer solstice on June 20 are about three times as intense as those at the winter solstice on December 21, due to the higher angle of the sun in the sky and longer daylight hours. This is why summers are warmer and winters are colder, irrespective of Earth’s changing distance from the sun.
Historically, many people have misunderstood the relationship between Earth’s distance from the sun and the seasons. A common misconception is that Earth is closest to the sun in summer and farthest in winter, but this is not the case. In fact, Earth reaches perihelion around January 4 and aphelion around July 3 or 4, dates that coincide roughly with major holidays in North America—New Year's Day and Independence Day in the United States, and Canada Day in Canada.
Joe Rao, a veteran meteorologist and astronomy writer for publications like Natural History magazine and Sky & Telescope, explains, “If you ask people in which month of the year they believe that the Earth is closest to the sun, most probably would say we're closest during June, July or August. But our warm weather doesn't relate to our distance from the sun. It's because of the 23.5-degree tilt of the Earth's axis that the sun is above the horizon for different lengths of time at different seasons.”
Rao also notes that the difference in distance from the sun between perihelion and aphelion is equivalent to about 16.62 light seconds, or roughly 3.1 million miles farther at aphelion. Despite this, the effect on Earth’s climate is subtle and secondary to the axial tilt.
Another interesting nuance is that the Northern Hemisphere’s summer in 2025 is about 15 minutes shorter than it was in 2024. This slight change is due to gravitational influences from the sun, moon, and Jupiter, which subtly alter Earth's orbital path and timing.
So, while the Earth is at its farthest point from the sun today, the blazing heat experienced across many U.S. states is a testament to the complex interplay of celestial mechanics and Earth’s axial tilt. The sun may be a bit smaller and dimmer in the sky, but the Northern Hemisphere is basking in the warmth of long, direct summer sunlight.
As we mark aphelion this July, it’s a perfect reminder that seasons are governed more by the tilt of our planet than by its distance from the sun. This distinction helps us appreciate the intricate dance of celestial bodies that shape life on Earth.
