Spring was ushered in at 6:28 this morning as the sun's most direct rays shined on the equator. This is known as the vernal (spring) equinox. The other time this occurs is for the autumnal (fall) equinox which will take place on September 22nd.
Here is what happens during the vernal equinox: The sun's most direct rays cross over from the southern hemisphere into the northern hemisphere. While this is happening, the sun is shining directly over the earth's equator, dousing the earth's northern and southern hemispheres in almost an equal amount of sunlight.
During the equinox, both day and night are balanced to almost 12 hours each all over the world, so instead of the Earth tilting away toward or from the sun, the Earth's axis of rotation is perpendicular to the line connecting the centers of the Earth and the sun during an equinox.
If you are in the northern hemisphere, daylight will continue to grow longer until the summer solstice, which occurs on June 21st. Expect the opposite to occur in the southern hemisphere. Daylight there will continue to grow shorter toward their winter solstice on the same day.
Happy first day of spring!