The March Equinox, also known as the Vernal or Spring Equinox, is a significant day in Sierra Leone because it marks the start of the spring season. This day usually falls between March 19th and 22nd. At this time, the sun crosses the celestial equator, making day and night approximately equal in length all over the world.

Sierra Leone, being near the equator, does not experience dramatic seasonal changes like countries in higher latitudes. However, this period often coincides with a change from the dry season to the rainy season.

Historically, Sierra Leoneans are known to have marked the changing of seasons with various local traditions and festivities although specifics may vary between different ethnic groups. Sierra Leone's diverse tribes such as Mende, Temne, Limba and others each have unique ways of celebrating this period.

Today, many people in Sierra Leone continue to observe these traditional practices intertwined with modern activities. Agriculturally-focused communities often prepare for planting crops at this time, leveraging on the rains that come with this new season.

In urban areas like Freetown or Bo City, while there may not be specific celebrations linked to the March Equinox itself; schools and institutions often use this period to launch environmental awareness campaigns or tree planting exercises - a nod towards both global climate consciousness and traditional associations with nature during this period.

While not a public holiday in Sierra Leone, the March Equinox remains an important marker of natural cycles that influence cultural practices and environmental activities across the country.