As we head further into the winter season, the daily temperatures are dropping but Earth is actually getting closer to the Sun.

An event that happens yearly in January is the Perihelion. This is the point at which Earth is closest to the Sun; about 3 million miles closer than at the Aphelion. The Aphelion, which occurs in July, is the point in time where Earth is furthest from the Sun.

So, if Earth is closer to the Sun during the Northern Hemispheric winter, why is it still cold here?

It’s all in the tilt. As we head further into the winter season, the Northern Hemisphere of Earth has tilted away from the Sun. The opposite happens for the Southern Hemisphere this time of year, giving them their warmer season.

Earth’s orbit around the Sun is not a perfect circle. The orbit is an elliptical shape which allows Earth to be at different distances from the Sun during certain points throughout the year. Although we’re technically getting closer to our main heat source this time of year, the temperatures vary due to the 23.5-degree tilt of Earth’s axis.

In fact, we wouldn’t experience our four seasons without Earth’s tilt! Earth’s tilt determines where the Sun’s warm rays are directed, or not directed, on Earth, helping temperatures to rise or fall.