The spring equinox doesn’t necessarily mean equal day and night
Spring is officially here — and a common misconception about the equinox is that we’ll see an equal amount of daylight and night on that day.
While that’s true for some locations, it’s not true everywhere. An equal 12 hours of daylight and 12 hours of night usually occurs in these days leading up to the first day of spring, and it all depends on your latitude.
In the United States, most cities will experience 12 hours between sunrise and sunset the Thursday or Friday before the first day of spring, depending on how far north or south you are. Then, the amount of daylight we see will continue to lengthen until the first day of summer, which is June 21 this year.
The changing amount of daylight is all because the Earth is tilted on its axis, and for all but two days of the year, the Earth’s axis tilts toward or away from the sun.
That Earth’s tilt is why the northern hemisphere sees more sunlight in the spring and summer months and less sunlight in the fall and winter, and if you’re looking for equal amounts of day and night, there are two days a year — shortly before the first day of spring and shortly after the first day of fall.