While not official dates, winter runs from Dec. 1 to the end of February for meteorologists in the Upper Midwest. The period is statistically our coldest 90 days of the year.
By astronomical calculation, winter arrived at 4:44 a.m. Wednesday. The Earth at that time reached the point in its revolution about the sun when the North Pole was inclined 23 ½ degrees away from the sun, giving those of us who live in the Northern Hemisphere our longest night and shortest day. We call this the December solstice and the beginning of winter in the Northern Hemisphere. We immediately gain a few seconds of daylight the next few days, and by Christmas Day we will have gained an entire minute of daylight. What a nice gift.
Astronomical winter begins on Dec. 21 or 22 each year, and at noon on the first day of winter the sun is 21 ½ degrees above the horizon in the Twin Cities and only 18 degrees at International Falls. The Twin Cities receives eight hours and 47 minutes of sunlight and the people in International Falls must get by with a half-hour less.
The weather typically continues to get colder for five more weeks even though our daylight begins to increase again after the winter solstice. The coldest days often arrive in late January. Usually there is a temperature lag of 30 to 40 days after the solstice that cools the air and ground as much as possible. Jan. 25 is statistically our coldest day of the year.
States such as Florida, Texas, Arizona, California and Hawaii sell sunshine and warmth, but for those of us who have to, or want to, live with winter, it is a remarkable season in Minnesota. Every year our winters come with snowflakes, icicles, beautiful white landscapes, cardinals at the feeders, squirrel and cottontail tracks, skiing and outdoor skating, and last year’s insulated jackets and wool overcoats.
Jim Gilbert’s Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.