Midwest Highlights - December 2014

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A Warm December

December temperatures across the Midwest region ranged from 3.3°F above normal in Kentucky (state average) to 6.6°F above normal for the month into Minnesota (state average) (Figure 1). For the region, December was 4.5°F above normal.  The largest temperature impacts were felt across Minnesota and Iowa.  December in Iowa came in at 5.5°F above average, with above normal temperatures on all but two days between the 4th and 28th. Periods averaging more than 10°F above normal (12th - 15th and 21st - 26th) brought overnight low temperatures frequently higher than typical daytime high readings.  In Minnesota, numerous records were set for maximum overnight temperatures (Figure 2). Additional temperature records were set across northern Illinois, north-central Indiana, and central Michigan on December 16th, 2014.  Because December began with below normal temperatures across the region (2° to 9°F below normal with coldest temperatures centered over the Upper Peninsula of Michigan and northern Wisconsin), and ended with temperatures above normal, the monthly ranking for December 2014 as one of the warmest December on records ranges from 13th warmest (Minnesota) to 26th warmest (Kentucky). As an entire region, it was the 16th warmest December on record. 

Annually for 2014, the region came in as the 7th coldest year on record (1895-2014).  Wisconsin is the state in the region that averaged the coldest temperature annually (40.2°F), coming in at 3.3°F below normal for the year, and Kentucky averaged the warmest temperature, 54.3°F, which is 1.6°F below normal. 

 

December Precipitation Below Normal

With above normal temperatures a majority of the month, much of December’s precipitation fell as rainfall and not snowfall.  This resulted in below normal accumulated snowfall values across much of the region (Figure 3). Across much of the region, more snowfall actually fell in the month of November than in December.  Total monthly accumulated precipitation was concentrated along the Ohio River Valley with observed values of 3.0” – 4.0” across southern Illinois, Indiana, Ohio, and most of Kentucky (Figure 4) primarily from events on December 1st, 2nd, and 6th.  Despite all precipitation, much of the region came in below normal for the month (Figure 5) with the central portion of the region 0.5” to 2.0” below normal.  December regional precipitation was 0.44” below normal.

Annually, the region had a +1.06” precipitation departure from normal; however, the states of Kentucky, Ohio, and Missouri came in below normal.  Wisconsin, Michigan, and Iowa all experienced precipitation at amounts much larger than the other states (departures greater than 3.5” from normal) with Wisconsin and Michigan having their 7th wettest year on record, and Iowa experiencing its 16th wettest year on record.
 

-OBK-

Parts of this report were provided by the Iowa Department of Agriculture and Land Stewardship and Minnesota HydroClim.