The Wheel of the Year is a metaphor for the cycle of the seasons. In both the Northern Hemisphere and Southern Hemisphere the wheel includes Spring, Summer, Autumn, Winter. The only difference is that the timing of the seasons is reversed. While it is Winter in one it is Summer in the other. In temperate zones the wheel may be more properly characterized by wet and dry seasons than by temperature changes.
In modern times we are less aware of the seasons; artificial light, food stores with imported produce, well insulated clothing and homes, and modern transportation distance us from the real world of seasonal changes. Time demands placed on us by jobs and school prevent from responding in a natural way to the seasonal changes.
Making a choice to consciously observe the seasonal changes may be as mild as charting the sequence of blooms or refusing to eat imported strawberries out of season or it may include profound spiritual beliefs and celebrations. Wherever one falls on the continuum we all benefit from a connection to the real world.