For those of us who live in Connecticut or the Northeast, after a long winter, one single date on the calendar seems to be the gateway to bliss. March 21st (or 20th or 22nd some years) is the first day of spring. Even though we didn’t actually have a real winter this year, that date still flirts with us and teases us and now, with less than a month to go, is within our grasp.
But March 20th, 2012 is only a date on a calendar. Yes, it matches up with where the Earth is relative to the sun. The spring or autumnal “equinox” being the first day of spring or fall and the “solstice” being either the first day of winter (shortest day of the year for us) or the first day of summer (longest day of the year).
But in the weather world, meteorological seasons do not quite match up to the calendar. Meteorological spring begins on March 1st and take takes us until about Memorial Day when we switch to meteorological summer, almost a month before the calendar says it’s summer.
This means when we are talking about the “real” winter, it’s December, January and February and the real summer June, July and August.
So why the difference? As it ends up, by March 1st we tend to see spring-like patterns developing across the United States and even our computer models begin to forecast for the change in season. And while we all know we can get nailed with monster snow storms in March, we tend to see the pattern changes evolve ‘during’ march versus the end of the month. Remember that the equator is constant all year round, but in the winter, it’s that buildup of cold, dense air in the north pole that drives weather across the country. When that cold air starts to weaken and recede as the north pole starts to tilt back toward the sun beginning after the first day of winter, winter weather tends to recede as well.
Strangely enough, it’s that retreating cold air plus spring-like temps coming up from the south that can lead to the really big snowstorms in March. So even though it might still feel like winter in March, spring is moving in as early as March 1st.
So…if you are fiending for spring, even though the calendar says you have to wait until the end of March, if you can make it another week until March 1st, you’re already there.