This is what people call “movement across latitudes”. Latitude is the position on the earth in relation to the equator. Zero degrees latitude means that someone is at the equator. The higher the latitude - IE, the further away from the equator - one goes, the colder it gets. This is simply because the equator gets the most sunlight, and the further away one goes, the less sunlight one is being exposed to. That said, there’s no real division of where one kind of climate or day ends and one begins.
There are three general zones, though. The first one is the arctic. This is the coldest zone; it generally starts around 66.5 degrees north or south, depending which end of the globe one is on. The second is the temperate; there’s no defined starting point for this one. Thirdly, there’s the tropics to either side of the equator.