News•April 15, 2014

March Was Coldest in U.S. Since 2002

The East vs. West weather divide that was in place across the contiguous U.S. throughout the winter lingered into March, with the eastern portion of the country trending colder than normal and the western portion still warmer than normal.

The temperature trends and rankings for each of the 48 contiguous states for March 2014. Colder-than-average temperatures in the East and warmer-than-average temperatures in the West persisted.
Credit: NOAA

For the lower 48 as a whole, this March was the coldest on record since 2002 (though it ranks as only the 43rd coldest in the longer-term records), according to the latest State of the Climate update from the National Oceanic and Atmospheric Administration (NOAA), released Tuesday. The average national temperature for the month was 40.5°F, 1°F below the 20th century average for the month. The Great Lakes and Northeast saw the coolest conditions, and Vermont actually saw its coldest March on record, with temperature 8.9°F below average.

California, on the other hand, saw its ninth-warmest March on record, with temperatures 4.7°F above average. The entire January-March period was warmer-than-average for the West, with Nevada, Oregon, and Utah each having one of their top 10 warmest winters and Arizona and California both seeing record warmth, with temperatures 5.2°F and 5.6°F above average, respectively.RELATEDMarch Was 4th Warmest on Record Globally
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The driving force behind this East-West divide were warm sea surface temperatures in the northern Pacific Ocean, which pushed the jet stream further north in western North America and further south in the East, said Jake Crouch, a climate scientist with NOAA’s National Climatic Data Center.

“It’s just sort of been a persistent pattern,” Crouch told Climate Central.

The heavy snowpack on the ground across much of the northern U.S. at the end of winter, as well as the record levels of ice covering the Great Lakes into spring, also likely influenced March temperatures in the Midwest and Northeast, as NOAA projected in its official spring outlook issued March 20.

The chilly March, of course, came against a backdrop of ever rising temperatures caused by the buildup of greenhouse gases in the Earth’s atmosphere. That background warming pattern doesn’t rule out the odd unusually cold month.

“Even though we do see a long-term warming trend in the U.S., any month can be colder or warmer than average,” Crouch said.

In fact, globally, this March was the fourth warmest on record, according to NASA data. And just 2 years ago, the U.S. saw its warmest March on record, with those records going back to 1895. Only three times since 2000 has March been colder than average, Crouch said.

No major precipitations trends were seen for the contiguous states in March, as the drought in California persisted.

“It’s kind of been the same story it’s been the past couple of months,” Crouch said. Despite some late-season storms, reservoir levels in California are well below what they typically are this time of year, and the water woes are only likely to worsen as he state exits its rainy season this month.

Drought is an issue the scientists behind the State of the Climate report will be paying close attention to in the coming months, Crouch said, as it creeps across more territory in the Southwest and Southern Plains, potentially affecting agriculture and wildfire seasons.