2012 a Record Warm Year for Continental U.S.

By: Christopher C. Burt , 8:36 PM GMT on January 02, 2013

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2012 a Record Warm Year for Continental U.S.

As most of you probably already know, 2012 has been the warmest calendar year on record for the continental U.S. according to NCDC data going back to 1895. The final actual average temperature for the year has yet to be tallied but as of Dec. 1st stood at 57.06°F (13.92°C), well above the previous record for the same time period (first 11 months of the year) of 56.05°F (13.36°C) set in 1934. What was truly astonishing, however, was the ratio of heat records versus cold records that was established over the course of the year.

Below is a chart of the total number of NCDC sites that measured daily and/or monthly record high and low temperatures. There are about 5,500 of these sites in the NCDC database all together and it is important to note that the first two columns of this table are not all-time record highs or all-time record lows but daily and monthly records. So, for instance, a single site may have broken dozens of daily records over the course of the year. The 5th and 6th columns are for all-time record highs and lows: a total of 362 such heat records and 0 such cold records occurred. The ratio of daily record highs to daily record lows (about 5 to 1) were the greatest for any year in NCDC records:



Below are two charts showing the ratio 1:1 of number of daily record highs versus daily record lows (top chart) and monthly record highs versus monthly record lows (bottom chart) for each decade since the 1920s. Note that we are only looking at two years so far this decade:





These charts were produced by Guy Walton of the Weather Channel.

The Weather Underground climate extremes database follows 298 significant city sites in the U.S. which represent all climate divisions and major population centers. More importantly, they all have long periods of record (POR’s) dating back to the 19th century in most cases.

This past summer some 22 of these 298 sites beat or tied their all-time absolute maximum temperature on record. This was the most since the infamous summer of 1936. No site recorded their coldest such.



The following cities from the WU database recorded their all-time single hottest month on record (no sites recorded their coldest month on record):



The last year that one of the 298 WU sites reported an all-time record cold month was 1994 when Caribou, Maine and Bayfield, Wisconsin recorded such. The last all-time absolute minimum temperature record for a specific WU site was on February 3, 2011 when Santa Fe, New Mexico fell to -18°F (-27.8°C). It was during that cold wave, you may recall, that Oklahoma set a new cold state record with a -31° (-35°C) reading at Nowata on February 10th.


Christopher C. Burt
Weather Historian

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5. WunderAlertBot (Admin)
8:49 PM GMT on January 04, 2013
weatherhistorian has created a new entry.
4. georgevandenberghe
8:49 PM GMT on January 04, 2013
Hay yields in Iceland are (or used to be) strongly positively correlated with summer temperatures. Does anyone know if this relation still holds?

December 2012 nighttime minimum temperatures have averaged the warmest of record in the DC area with only light freezes so far the entire winter. "Light freezes through December" is not unprecedented but it is very unusual in the DC area.

This December anomaly though is "weather" rather than "climate". During the next two months of winter I expect a few days of more typical extremes which here means a night or two below -10C. Ask Alaskans how very mild (NOT!!) December was this year and you'll get an earful.


Member Since: February 1, 2012 Posts: 19 Comments: 3070
3. Irpsit
5:54 PM GMT on January 04, 2013
I felt I should upload this comment because of the magnitude of climatic changes now occurring in Iceland where I live.

First, the increase if yearly temperature here, is significantly larger compared to rest of Europe or the United States.

This winter in south Iceland we almost have not got any snow nor cold. This is because the jet stream has been carrying more and more heat every year, and therefore while under the influence of the jet stream it rains instead of snow. When under the influence of polar air, it is not as cold as it used to be.

Furthermore, summer and transition seasons have been getting way warmer in recent years. This is having a dramatic impact in glaciers. The balance of snow over the year is negative, but the end result you see is really dramatic. I here talk that the predictions for the disappearing within 200 years of the half mile ice caps of Iceland is really occurring (though I did not believe it when I first read it)
Member Since: July 25, 2009 Posts: 0 Comments: 1
2. ARiot
1:57 PM GMT on January 03, 2013
Quoting maxcrc:
Daily records are more statistics than climatology, since in 365 days of the year, even the stations with longest series (100-150 years) statistically should beat few of them every year.
The all-time records are climatically more meaningful and ,once again, more than ever, merciless : 362-0.
As there are still fanatics waiting for the end of the world at any Maya-Aztec-Nostradamus prediction, there are funny folks believing a new ice age is coming, despite a streak of overwhelming data showing the opposite.


I agree, and yes, we are past many tipping points.

I also agree a global "ice-age" with mile, thick glaciers creeping south is out of the question for perhaps thousands of years. However, we don't know exactly how AGW, ocean acidification, massive melt /fresh water feedbacks will impact densely populated regions. So our great grandkids could, in theory, see a western Europe that is as cold as its lattitude would indicate, rather than how it has been since modern man.

The dice are loaded and rolling :-)
Member Since: June 24, 2012 Posts: 0 Comments: 366
1. maxcrc
3:23 AM GMT on January 03, 2013
Daily records are more statistics than climatology, since in 365 days of the year, even the stations with longest series (100-150 years) statistically should beat few of them every year.
The all-time records are climatically more meaningful and ,once again, more than ever, merciless : 362-0.
As there are still fanatics waiting for the end of the world at any Maya-Aztec-Nostradamus prediction, there are funny folks believing a new ice age is coming, despite a streak of overwhelming data showing the opposite.
Member Since: February 9, 2011 Posts: 0 Comments: 213

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About weatherhistorian

Christopher C. Burt is the author of 'Extreme Weather; A Guide and Record Book'. He studied meteorology at the Univ. of Wisconsin-Madison.