As we rotate around the sun, we are not going in a perfect circle, so at one point, the north will tilt away, causing shorter days, as we move further away in our rotation, it becomes colder, as we start to tilt back towards the sun the days become longer, and the closer we move in our rotation, it becomes warmer. That is why even though the longest day in daylight hours is in june, our rotation is still drawing us closer, so it is warmer, even though less hour of sunlight. Vise versa for winter, the days start getting longer in december, but we are colder in january and feb,up until march
