U.S. Has Warmest Year-to-Date As Drought Expands

By Andrew Freedman

The U.S. continued its hot streak through June, recording the warmest January-to-June period on record, with drought conditions spreading across the Lower 48 states to an unprecedented degree. According to statistics released Monday by the National Oceanic and Atmospheric Administration (NOAA), June was the 14th warmest such month on record, and the past 12 months were the warmest such period on record. At the end of the month, 56 percent of the country was experiencing drought conditions, which NOAA said was the largest drought footprint of the 21st century.

Chart of the warmest 12-month periods on record in the U.S. Credit: NOAA/NCDC.

Thanks to an intense heat wave that struck during the second half of June and only just subsided, more than 170 all-time high temperature records were set or tied across the country during the month. Many cities across the country, from Albuquerque, N.M., to Washington, D.C., experienced June temperatures that were far above their typical values.

“In some locations, 2012 temperatures have been so dramatically different that they establish a new 'neighborhood' apart from the historical year-to-date temperatures,” a NOAA report said. 

The warm June followed the warmest spring on record, which was the culmination of the warmestMarch, third-warmestApril, and second-warmestMay. This marks the first time that all three months during the spring season ranked among the 10 warmest, since records began in 1895.

In June, said NOAA scientists, the average daily temperature for the lower 48 states was a full 2.0°F above the 20th-century average. 

The U.S. Climate Extremes Index, which tracks the highest and lowest 10 percent of extremes in temperature, precipitation, drought and tropical storms/hurricanes, was a record-large 44 percent during the January-to-June period. That was more than twice the average value, driven largely by warm daily high and warm overnight low temperatures.

A scientific panel known as the U.S. State Climate Extremes Committee is reviewing a temperature reading of 113°F in South Carolina, and 112°F in Georgia, to determine if they qualify as the warmest temperature ever recorded in those two states.

Chart of how 2012's temperatures stack up against other warm years in Chicago. Click on the image for a larger version. Credit: NOAA/NCDC.

What’s more significant is that the January-June period was the warmest such period since 1895; ditto for the 12-month period from July, 2011 through last month. Every state across the Lower 48 states had warmer-than-average temperatures during the July 2011 to June 2012 period, except for Washington, where temperatures were near normal.

Colorado, by contrast, had its warmest June on record, with temperatures averaging 6.4°F above average. Seven other Western states had a top 10 warm June. It was also extremely dry in the West, which led to the devastating wildfires that erupted in Colorado, including the deadly Waldo Canyon Fire in Colorado Springs. In Colorado Springs, the average June temperature was 5.4°F above average, which was the warmest in 64 years. 

Across the country, wildfires burned more than 1.3 million acres during June, the second most on record for the month.

Nationwide, the news wasn’t much better when it came to precipitation: thanks to the 10th driest June on record (precipitation nationwide was about 20 percent below average, or 2.27 inches vs. a normal 2.89). By itself, that might not have meant much, but with the West (excluding the West Coast) experiencing either record or near-record dry conditions, and with low precipitation in many areas over many preceding months, more than half the nation (56 percent, to be precise) was officially in drought, according to the U.S. DroughtMonitor. That’s the largest “drought footprint” of the 21st century, notwithstanding the terrible droughts that plaguedthenationlastyear.

The most recent U.S. Drought Outlook doesn't offer much hope for the High Plains and much of the West. Credit: NOAA/CPC.

Some of the most intense heat during June was felt from the Plains to the Midwest. In Chicago, the average temperature during the month was nearly 7°F above average, which was the warmest June in 54 years. In Fargo, N.D., and Des Moines, Iowa, June temperatures were also 7°F or more above average. It was the warmest June in Fargo in 71 years.

Even International Falls, Minn., located at the border with Canada and widely referred to as the “nation's icebox,” had temperatures that ran more than 6°F above average for the month, which was the second-warmest in 78 years there. In Washington, D.C., which experienced record-breaking heat in late June into early July, the month of June was the warmest in 67 years, and the January-to-June period was the warmest such period on record.