WSET.com - ABC13The Fallacy of Spring by Sean Sublette

It happens every year.

The spring equinox comes in middle to late March and there is a collective sigh of relief: Winter is over!

Invariably, there are cold spells at the end of March, through April, and occasionally, into May.  And without fail, there are people who say something to the effect of, "Doesn't Mother Nature know that it's spring?"

Which tells me something about spring: It has a good public relations agent.

Think back to when you learned about the seasons in school.  We are taught that spring is the time when the flowers come out, the weather turns warmer, and everything begins anew. How comforting!  Almost like a fairy tale:  We have been released from the evil clutches of Old Man Winter.  It will not be cold anymore!  There's no way it can snow!

Like most fairly tales, this one is a romanticized dream. 

Spring is a battle.  It is a battle here in the middle latitudes between the stubborn cold air of the polar regions and the warmer air escaping its sequestration in the tropics.  Of course, the warmer air always wins the battle in the end.  After all, it has the sun on its side.  But exactly when that battle ends varies from year to year.

With each passing day of the spring, there is a little bit more daylight and the sun gets slightly higher in the sky.  This means that, little by little, more heat is coming into the Northern Hemisphere.  So every day, the average temperature of the hemisphere goes up a little bit.

But as we say in the science business, the relationship is non-linear at any one particular location in the hemisphere.  Some days, the cold air is very stubborn.  Other days, you can imagine that the cold air has been defeated for the season.  As a result, occasional big swings in temperature from day to day are to be expected.  That is to say, it is perfectly normal.

And like any long, drawn-out battle, there will be relative periods of quiet and relative periods of great turmoil.   Those sunny days in the 60s are nice, but there is a reason more tornadoes and damaging thunderstorms happen in spring than in any other season.  The battle rages.

But have faith.  As the battle wears on, the grip of the cold air will gradually get weaker and weaker.  The great turning point of this battle is the date of the last freeze or frost.  In our part of Virginia, that usually comes in middle to late April.

After a couple of months, the battle usually ends in a quiet whimper.  You look around one day in late May or early June and realize you haven't put on a jacket in a while.  Summer always arrives. 

Then you can complain about how hot it is.