Brief by Central Staff
Climate – February 1998 – Colorado Central Magazine
Perhaps the best that can be said of February is that it is short, although it is long enough to have a legal holiday, Presidents’ Day on the 16th, and an unofficial holiday, Groundhog Day on the 2nd.
As the story goes, the hibernating groundhog emerges from his burrow on this day. If the sun is shining — that is, he can see his shadow — then six more weeks of winter loom, and the critter returns to his burrow for more sleep. Otherwise, he presumably gets a cup of coffee and rises for the season.
At first glance, this legend appears to be a promotion concocted by the chamber of commerce in Punxsutawney, Pennsylvania — akin to jackalopes and fur-bearing trout.
But Groundhog Day has deeper roots. On the Roman Catholic liturgical calendar, it’s Candlemas Day, for consecrating candles that will be used in services later that year. The candle custom may have been borrowed from the Romans, who annually set aside a long winter night for burning candles to frighten away evil spirits.
Candlemas Day, on the old Scottish calendar, was one of four mid-season Quarter Days; the others were Whitsunday on May 15, Lammas Day on August 1, and Martinmas Day on November 11. The Scots had a proverb: “If Candlemas Day be wet and foul, the half o’ winter was gone at Yule.”
So did the Germans: “The badger pops out of his hole on Candlemas Day, and if he finds snow, walks abroad; but if he sees the sun shining he draws back into his hole.”
We have no groundhogs (Marmota monax) in Central Colorado, but this is prime habitat for a close relative, the yellow-bellied marmot, familiar to every mountain hiker. The furry two-foot-long rodent is also known as a rockchuck, whistle pig, or Marmota flaviventris.
However, it’s rather unlikely that one would appear in February, even for a quick peek at his shadow, since they hibernate for six to eight months each year and seldom emerge until late May. The most extensive research on marmots has been conducted at the Rocky Mountain Biological Laboratory at the old mining camp of Gothic in Gunnison County.
Even without a Marmot Day, it is still a regional custom to converse about the weather in February, and one occasional topic is “How much higher would the suicide rate hereabouts be if we didn’t have a February Thaw?”
Along about the 20th, the days are noticeably longer, the winds may abate for a few days, even in South Park, and the sun shines brightly — more blizzards loom, but the worst of winter is over, and postponed outdoor chores are almost pleasant.
Or at least it seems that way. But the greatest change in the length of the day occurs in March. In Salida, the day is 11.36% longer at the end of March than at the start; February, though, ties for second with October at 10.51%.
The length of the day changes with latitude — Leadville gets about 10 minutes’ more sunshine than Alamosa on June 21, and about 10 minutes less on December 22 — but no matter where you live in the Northern Hemisphere, the length of the day changes more in March than during any other month.
What about temperature? After gathering some data, we discovered that the monthly mean temperature hereabouts rises more (as a percentage) from February to March than at any other time. The biggest drop is from October to November.
So no matter what any local marmot suffering from insomnia might see in the way of shadows on February 2, there is a February Thaw — in an average year, anyway.