Why is it cold in winter?

Not because Earth is further from the Sun. It is the tilt. Earth leans on its axis, and in winter your half of the world is leaning away.

So sunlight arrives at a shallow angle, spread thin across the ground, and the days are shorter, leaving less time to warm up. On the solstice your half leans furthest away and the day is the shortest of the year. The very next day, the light begins coming back.