OTTUMWA — By this time of year, most people in Iowa are willing to at least ponder a basic question: When will winter end? But have you ever thought about what winter is?
Astronomical winter runs from the shortest day of the year (Dec. 21 or 22) through the spring equinox (March 20 or 21). The date varies slightly by year because it takes the earth's orbit around the sun doesn't quite line up with the calendar.
But weather helps define winter, right? Cold temperatures, snow, the reluctance of the car to start after a frigid night. And that can all happen well before December 21 and usually departs before March 21.
The weather involves a different winter: Meteorological winter. And defining that isn't as simple as looking at where and when the sun rises. Dates vary. Most define meteorological winter as the months of December, January and February. Winter weather can certainly hit outside of those months, but that's when the cold and snow are most common.
While astronomical winter arrives everywhere in the northern hemisphere at the same time, meteorological winter does not. The National Oceanic and Atmospheric Administration (NOAA) says winter varies depending on where people live. The farther north you are, the sooner meteorological winter begins.
By that same token, the farther south you are the sooner meterological winter ends. But Iowans shouldn't expect much of a break. Most observers still say the end of February brings the end of meterological winter in this part of the country.
Since 2012 is a leap year, that means one extra day of winter.