Author: Mary Knapp

In the astronomical world, the vernal equinox marks the beginning of Spring. On the equinox, the sun crosses the celestial equator on its way north. For the northern hemisphere, this marks the beginning of the spring season. Days gradually get longer and the nights shorter. With the longer days, warmer temperatures become more common. The term “vernal equinox” comes from Latin, with “vernal” meaning “spring” and “equinox” meaning “equal nights”. The day and night aren’t exactly equal, as the sun is a disk rather than a point. Still at this time of the year, and at this latitude, we are adding approximately 2 minutes of daylight per day.

Spring Equinox from space. NASA, March 20, 2011.

Mary Knapp, Weather Data Library