Speaking of planetary tilt, the northern hemisphere is finally getting longer days, and as bad as winter may seem, I’d like to let you know it could be worse. It turns out, the northern hemisphere has an ever so slightly less frigid winter thanks to a trick of geometry. 

Each year, at the beginning of January, Earth has its closest approach to the Sun, bringing us a tiny bit of extra light. This year, the closest approach, or perihelion, occurred on January 2. Now, we are on the retreat from the Sun, but since there is only a small difference between our closest and farthest distance from the Sun, the tilt of the planet is the thing setting our seasonal thermometer.

More Information

EarthSky article