March runs 31 days and takes its name from Mars, the Roman god of war. In the earliest Roman calendar, March was actually the first month of the year — which is also why the later months September through December carry names meaning “seventh” through “tenth,” counting from March rather than January.
This month marks a genuine turning point in the seasons. In the Northern Hemisphere, the spring equinox falls in mid-to-late March, when day and night are roughly equal length before daylight starts pulling ahead — the traditional start of spring. In the Southern Hemisphere, the same equinox marks the start of autumn, as days there begin shortening toward winter.
March is associated with the shift out of winter across much of the Northern Hemisphere: melting snow, lengthening days, and the first signs of new growth. Many cultures mark the changing season with festivals around the equinox, and in several countries March also carries civic or cultural significance tied to the turn of the seasons. Weather in March tends to be transitional and changeable, a reputation captured in the old saying that March “comes in like a lion and goes out like a lamb,” referring to its unpredictable mix of lingering winter storms and early spring warmth.