<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
Why is the northern hemisphere winter solstice in December, but late January and early February are always the coldest times of the year?
<|assistant|>
The northern hemisphere winter solstice takes place in December because the earth's axis is tilted relative to the sun. This tilt causes the days to get progressively shorter in December, culminating in the solstice, when the amount of daylight is at its lowest point. Meanwhile, during January and February the sun is at its lowest point in the sky, causing temperatures to cool significantly.