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NOAA: 2012 Hottest & 2nd-Most Extreme Year On Record

It’s official: 2012 was the warmest year on record in the lower 48 states, as the country experienced blistering spring and summer heat, tinderbox fire weather conditions amid a widespread drought, and one of the worst storms to ever strike the Mid-Atlantic and Northeast.

According to the National Oceanic and Atmospheric Administration (NOAA), 2012 had an average temperature of 55.3°F, which eclipsed 1998, the previous record holder, by 1°F. That was just off Climate Central’s calculation in mid-December, which projected an expected value of 55.34°F, based on historical data. 

The 1°F difference from 1998 is an unusually large margin, considering that annual temperature records are typically broken by just tenths of a degree Fahrenheit. In fact, the entire range between the coldest year on record, which occurred in 1917, and the previous record warm year of 1998 was just 4.2°F. 

The year consisted of the fourth-warmest winter, the warmest spring, second-warmest summer, and a warmer-than-average fall. With an average temperature that was 3.6°F above average, July became the hottest month ever recorded in the contiguous U.S. The average springtime temperature in the lower 48 was so far above the 1901-2000 average — 5.2°F, to be exact — that the country set a record for the largest temperature departure for any season on record.

"Climate change has had a role in this [record],” said Jake Crouch, a climate scientist at NOAA's National Climatic Data Center in Asheville, N.C. He said it isn't clear yet exactly how much of the temperature record was due to climate change compared to natural variability, but that it's unlikely such a record would have occurred without the long-term warming trend caused in large part by emissions of greenhouse gases.

During the summer, nearly 100 million people experienced 10 or more days with temperatures greater than 100°F, which is about one-third of the nation’s population, NOAA reported.

With 34,008 daily high temperature records set or tied the year compared to just 6,664 daily record lows — a ratio of about five high temperature records for every one low temperature record — 2012 was no ordinary weather year in the U.S. It wasn’t just the high temperatures that set records, though. Overnight low temperatures were also extremely warm, and in a few cases the overnight low was so warm that it set a high temperature record, a rare feat.

Even more astonishing is the imbalance between all-time records. According to data from NOAA's National Climatic Data Center, there were 356 all-time high temperature records set or tied across the entire U.S. in 2012, compared to four all-time low temperature records. All of the all-time record lows occurred in Hawaii.

As the climate has warmed during the past several decades, there has been a growing imbalance between record daily high temperatures in the contiguous U.S. and record daily lows. A study published in 2009 found that rather than a 1-to-1 ratio, as would be expected if the climate were not warming, the ratio has been closer to 2-to-1 in favor of warm temperature records during the past decade (2000-2009). This finding cannot be explained by natural climate variability alone, the study found, and is instead consistent with global warming.

Driven largely by the warm temperatures and the massive drought, one measure of extreme weather conditions, known as the Climate Extremes Index, shows that it was the second-most extreme year on record, second only to 1998. Studies show that in response to global warming, some extreme events, such as heat waves, are already becoming more likely to occur and more intense.

Nineteen states had their warmest year on record in 2012, mainly in the Plains and Midwest, where summer heat and drought was the most intense. An additional 26 states had one of their top 10 warmest years on record. Remarkably, every state in the lower 48 experienced an above-average annual temperature.

The extreme heat is even more vivid when examined at the local level. Cities such as New York, Boston, Washington, Milwaukee, St. Louis, Denver, Des Moines, and Chicago all set records for their warmest year.

Marquette, Mich., which is well-known for its cold and snowy winters, not only set a record for the warmest year, but also set a record for the most amount of days above freezing (32°F) in a single year, with 293 such days, and the number of consecutive days above freezing, with 237.

In Des Moines, which set a record for its warmest year smashing the old 1931 record by 1.5°F, it was the first year not to reach 0°F. In addition, March had the largest monthly temperature departure from average of any month on record there, coming in at 16.4°F above average.

The year was also characterized by extreme drought, and two states — Nebraska and Wyoming — also had their driest year on record. Eight more states had annual precipitation totals that ranked in the bottom 10.

At its maximum extent in July, drought conditions encompassed 61 percent of the nation, with the most intense conditions in the Great Plains, West, and Midwest. The nationally averaged annual precipitation total was 2.57 inches below average, making 2012 the 15th-driest year, and the driest year since 1988, which also featured a major drought.

The drought of 2011-12, which is still ongoing, is comparable in size to severe droughts that occurred in the 1950s, and is already being blamed for more than $35 billion in crop losses alone, according to the reinsurance company Aon Benfield. In fact, it’s quite possible that damage from the drought will eclipse the total bill from Hurricane Sandy, which some estimates place at more than $100 billion. Overall, the drought could end up robbing the limping U.S. economy’s GDP of a full percentage point, said Deutsche Bank Securities.

The drought was instigated in large part of very low snow cover and warm temperatures during the winter of 2011, and record warmth during the spring, which allowed for an early start to the growing season and depleted soil moisture earlier than normal. The record March heat wave put the drought into overdrive, accelerating its development across the Plains and Midwest in particular.

The drought conditions created ideal conditions for wildfires, as 9.2 million acres went up in smoke in the West, the third-highest on record.

The same weather patterns that led to the drought helped suppress severe thunderstorms and tornadoes, with a final tornado count that is likely to be under 1,000, which would be the fewest twisters since 2002.

According to NOAA, the year saw 11 natural disasters that cost at least $1 billion in losses, including Hurricane Sandy, which struck the Mid-Atlantic and Northeast on October 29-30.

Globally, 2012 is expected to be ranked as the eighth-warmest year on record, with that announcement coming later in the month.

Related Content:
Sandy Tops List of 2012 Extreme Weather and Climate Events
Four Major Heat Records Fall in Stunning NOAA Report
Book It: The Hottest Year on Record
2012 Heat Wave is Historic, If Not Unprecedented
Coverage of 2012 Summer Heat Waves
U.S. Drought is Most Severe Since 1950s, Report Says
Ongoing Coverage of Historic Drought in U.S.
NOAA: 2012 To Rank as Second Costliest Year Since 1980


By Kevin Rosseel (20009)
on January 8th, 2013

Excellent graphics as usual, very compelling and attractive. Thanks for improving even on NCDC’s figures. -Kevin

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By Christine Potochny (Washington, DC 22202)
on January 9th, 2013

For those interested, WRI has a great “Extreme Weather”  timeline at
(Disclosure: I work at WRI).

Reply to this comment

By Scott Hollington (Minneapolis)
on January 9th, 2013

every year I read that “this was the hottest year ...” the northern hemisphere north America Europe

2012 was a warm year in the continuous 48. 
But not Alaska.
And if you include Alaska, it suddenly was not that warm of a year.
Yet there is no mention of this in your article.


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By Andrew
on January 9th, 2013


Even if you include Alaska and Hawaii you end up with a remarkably warm year. We did not include those two states because NOAA uses the lower 48 states in its official stats, and we took our cue from them.

You’re correct that it was cooler than average in Alaska, but that does not balance out the warmth in the rest of the country.


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By Tom
on January 10th, 2013

Remarkable.  Remarkable graphs.  Of course scaling makes all the difference in making it look dramatic.  And of course the continental US only comprises something like 2% of the earth’s surface.  But hey, who’s counting.  We’ve seen temperatures rise and fall - but generally rise steadily since the late 1800s (well before copious amounts of anthropogenic co2 hit the atmosphere).  So is it any surprise that the temperatures are higher at the terminal point of a warming trend than they are at the beginning?  One warm year in 2% of the globe’s surface is proof of AGW but the last 15 years of flat temps somehow are not adequate evidence to falsify AGW.  Nor are falling temps from 1940 to the late 70s when anthropogenic co2 output rose at a rapid rate.  Lol.  You guys are a joke.  A bad one.

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By Brock Peterson (Lyons)
on January 10th, 2013

Rain is a closed system right ? Evaporation happens rain falls, so the rain has to go somewhere! Where did it all go ....someone must be getting our rain! Who in the world experienced greater than normal rainfall…we find out and just go get it back! smile

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By Paul Budline (Princeton, NJ)
on January 10th, 2013

China is having its coldest winter in three decades, which doesn’t prove much of anything.  But it illustrates the fundamental dishonesty of your site and your “reporting.”  If the Chinese were dying from record heat, it would be a headline here; instead, you cherry pick the relative warmth of CONUS, a relatively tiny land mass.  Here is some other news from around the world:

“The bitterly cold air so far this season has been bottled up in Alaska and in Asia. China is suffering through the coldest winter in 28 years. It has been so cold that Laizhou Bay (the large bay east of Beijing) has frozen over in coastal locations, trapping around 1,000 ships. A severe cold snap across Russia into Eastern Europe has been blamed for over 200 deaths. The Russian city of Ojmjakon in Siberia, often called the coldest town on Earth, recently recorded a low of minus 73 degrees.”

When record cold hits, it’s “natural variation.”  When record heat hits, it’s “climate change.”  Meanwhile, the guru of AGW, one Al Gore, has become even more of an object of derision than ever before.  These are cold days indeed for the AGW religious zealots.

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By Karl
on January 10th, 2013

So what would the temperature have been without NOAA’s latest revision?

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By Phil (Jacksonville Ga)
on January 13th, 2013

If higher temperatures are correlated with increasing CO2, why were temperatures essentially flat from 1920 to the mid 1980’s?

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By John Nada (Chicago)
on January 14th, 2013

There is a bug in your matrix : your chart shows the temperature in 2006 was .01 degree LOWER than 1998. SInce it doesnt fit your bogus AWG propaganda, you just inversed 2006 and 1998 to make the curve continuously increasing. Smart! quite typical of the solar activity deniers LOL

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By leonard (prague/austria/02110)
on July 11th, 2014

Of course, NOAA revised these numbers. According to NOAA, 1936 was actually the hottest year in the US.

NOAA describes on its site how it adjusts temperatures after 1950 upward. If you look at the raw data, the temperature is going down. One has to trust that NOAA’s changed temperature data is accurate and moreover, that their historical data from 1895 to 1961 is accurate.

Also note that they define the average or “normal” temperature as the average temperature from 1961-1980.

The truth is that noone cane definitively state with accuracy of .1 degree celsius what the temperatures were across the entire US for the past 100 years. They are estimation with very large error bands.

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