Spring officially starts on Monday March 20th at 5:24pm in Baltimore. It lasts until June 21st. A lot of averages change during that time.
For example Our average high goes from 56° on March 20th to 86° on June 21st! That isn't a guarantee that we will hit those numbers, although we will be close to that on Monday. It does give you a sense of how much change we can see in those three months.
Spring is often associated with showers. We typically add 11.25" of rain over those three months. It actually isn't the wettest season though. That belongs to summer.
If you want to learn more about about the daylight we get around the equinox, meteorologist Cesar Cornejo wrote a great article here: Near equal amounts of sunlight and darkness today, not the equinox
