Meteorological Winter begins Wednesday! A look ahead at December
OMAHA, Neb. (WOWT) - December 1st kicks off meteorological winter in the northern hemisphere. The start of astronomical winter this year – the winter solstice – occurs on December 21st.
(You can review the difference between astronomical and meteorological seasons at the bottom of this article.)
On average, Omaha starts the month of December with highs in the lower-40s and ends the month with highs in the mid-30s. Our average lows drop from the mid-20s to the mid-teens by December 31st.
We only lose about 10 minutes of total daylight between the start and end of the month with December 21st marking the “shortest” day of the year. In Omaha, that amounts to 9 hours and 11 minutes of daylight on the solstice.
December kicks off our three snowiest months in Omaha, with an average of 5.8 inches of accumulation.
The monthly temperature outlook from the Climate Prediction Center forecasts a warmer-than-average December here in the Heartland. This does not mean we won’t have dips and cold spells... It is December after all. However, the start of the month is definitely starting on a warm note!
The monthly precipitation outlook shows no strong signal for wetter or drier than average conditions locally.
Though our daylight hours start to increase after the solstice, our average temperatures continue to drop through mid-January before gradually warming back up for the remainder of meteorological winter.
ASTRONOMICAL VS METEOROLOGICAL SEASONS
Astronomical seasons are caused by the tilt of the Earth on its axis as it rotates around the sun; these are the seasons you may see on a calendar.
Equinoxes occur when the sun passes directly over the equator – marking the start of the astronomical spring and fall seasons. Day and night are roughly the same length (12 hours) around the equinox.
Solstices occur when the sun’s apparent path is the farthest north or south of the equator. Solstices mark the start of the astronomical winter and summer seasons – or the “shortest” and “longest” days of the year.
Meteorological seasons are used primarily for the documentation of climate information. Each season is a nice, even 3-month period, falling more in line with our civil calendar.
While the start of astronomical seasons will change a few days from year to year, meteorological seasons will always start on the first days of December, March, June, and September - respectively.
Less variation in season start dates and season duration allow us to more easily compare climate statistics from year to year.
More information on astronomical and meteorological seasons can be found here.
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