Jun 12, 2018

Hot streak: U.S. sets records for warmest 3, 4, and 5-year periods

Temperature rankings for the contiguous U.S. during the past 48 months. Credit: NOAA/NCEI.

With May 2018 ranking as the warmest such month on record in the continental U.S., beating out the Dust Bowl May of 1934, the country has extended a much longer heat streak. According to the National Oceanic and Atmospheric Administration, the country has had its warmest 3-year, 4-year, and 5-year periods on record through May 2018.

Why it matters: The unusually mild temperatures are one way that global warming is affecting the U.S., as long-term temperatures trend higher. Even if individual months fail to break a heat record, such as April 2018, the long-term trend is clear.

What they found: Recently released NOAA data show that May 2018 was 5.21 degrees Fahrenheit above the long-term average in the U.S., taking the top spot.

  • Every state in the lower 48 had above average temperatures for the month, and eight states set monthly records.
  • During the month, there were more than 8,590 daily warm temperature records set or tied, compared to just 460 daily cold temperature records during the same period.

The NOAA report also shows that the past 36 months, from June 2015 through May 2018, had a temperature anomaly of 2.6 degrees Fahrenheit above average, qualifying as the warmest 36-month period since reliable instrument records began in 1895.

  • The past 48 months, from June 2014 through May 2018, have also been the warmest such period on record.
  • The same is true for the past 60 months, dating back to June 2013.

The big picture: The report, a summary of temperature statistics and rankings through May, does not attribute the temperature trends to global warming or any other causes, but the consistency of the record warmth is in line with expectations from the record amounts of greenhouse gases in the air.

Globally, the past few years have been some of the hottest years on record, as long-term climate change has combined with natural climate phenomena, such as El Niño, to produce record-shattering temperatures. The year 2016 was the warmest on record, and 2018 is expected to be another top 5 warmest year.

Average annual temperatures from 1895 through 2017, showing the warming trend throughout the period. Credit: NOAA.

Nationally, 8 of the 10 warmest years have occurred since 1998.

What to watch: According to the Climate Science Special Report of the government's Fourth National Climate Assessment, the average temperature of the U.S. during the 2021 to 2050 period is expected to be close to what is now considered a record warm annual average temperature.

“In other words, recent record-breaking years may be ‘common’ in the next few decades."

The same report also warns that heat waves will be more intense, frequent and longer-lasting in coming decades.

Go Deeper: NOAA National Temperature Rankings.

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Trump says he will campaign against Lisa Murkowski after her support for Mattis

Trump with Barr and Meadows outside St. John's Episcopal church in Washington, D.C. on June 1. Photo: Brendan Smialowski/AFP via Getty Images

President Trump tweeted on Thursday that he would endorse "any candidate" with a pulse who runs against Sen. Lisa Murkowski (R-Alaska).

Driving the news: Murkowski said on Thursday that she supported former defense secretary James Mattis' condemnation of Trump over his response to protests in the wake of George Floyd's killing. She described Mattis' statement as "true, honest, necessary and overdue," Politico's Andrew Desiderio reports.

8 hours ago - World

The president vs. the Pentagon

Trump visits Mattis and the Pentagon in 2018. Photo: Brendan Smialowski/AFP via Getty

Over the course of just a few hours, President Trump was rebuffed by the Secretary of Defense over his call for troops in the streets and accused by James Mattis, his former Pentagon chief, of trampling the Constitution for political gain.

Why it matters: Current and former leaders of the U.S. military are drawing a line over Trump's demand for a militarized response to the protests and unrest that have swept the country over the killing of George Floyd by police.

New York Times says Tom Cotton op-ed did not meet standards

Photo: Avalon/Universal Images Group via Getty Images)

A New York Times spokesperson said in a statement Thursday that the paper will be changing its editorial board processes after a Wednesday op-ed by Sen. Tom Cotton (R-Ark.), which called for President Trump to "send in the troops" in order to quell violent protests, failed to meet its standards.

Why it matters: The shift comes after Times employees began a coordinated movement on social media on Wednesday and Thursday that argued that publishing the op-ed put black staff in danger. Cotton wrote that Trump should invoke the Insurrection Act in order to deploy the U.S. military against rioters that have overwhelmed police forces in cities across the country.