Then, like a Hallmark movie without the fairy-tale end, it left us, and did not look back. Not even now — on the eve of the vernal equinox — has the season shown a hint of regret and willingness to return.
“Spring” begins today, they say, but yet another winter storm with yet another foot of snow is rolling up the East Coast this week. High temperatures are going to be in the 40s in Washington and New York City through the end of the week.
So color us skeptical.
At 12:15 p.m. Tuesday, the sun will be directly above the equator on its way into the Northern Hemisphere. Because Earth has a 23.5-degree tilt, the hemispheres get different amounts of sunlight through the year. On the equinox, however, neither hemisphere is tilted toward or away from the sun, and, as a result, each hemisphere receives roughly equal amounts of daylight and darkness.
Here in the Northern Hemisphere, daylight is rapidly increasing. Washington gains 2 minutes and 33 seconds of daylight per day in mid-March. Northern U.S. cities are racking up close to 3 minutes or more.
But it is not necessarily getting much warmer, as we have experienced over the past few weeks. While the increasing daylight and higher sun angle eventually usher in warmer weather, spring tends to be slow to start. In most of the Lower 48, spring is actually a few degrees colder than fall, despite the days being much longer. In Washington, meteorological spring averages 3 to 4 degrees colder than fall.
This year, the cold weather is mostly due to what is going on in the atmosphere. The pattern in March has been exceptionally winterlike. But, in general, there is a seasonal temperature lag that also comes into place.
Even though there is more solar radiation coming in during the spring, it takes a while for the weather to warm up. A lot of energy is needed to heat water — and there is a lot of water on our planet. The opposite is true in the fall, when temperatures are slow to cool off because the oceans hang on to heat longer.
It is no surprise, then, that the March equinox is significantly colder than its September counterpart. The spring equinox, on average, is 15 to 30 degrees colder than the first day of fall across nearly all of the Lower 48.
We are certainly feeling that difference this week, holding out hope that spring weather will return in April. We will be here, waiting, with open arms.