Looking back at U.S. Climate in 2018

Although most people tend to look back and on the past year around the holidays and at the beginning of a New Year, I also like to reflect back once spring has truly sprung. The sun illuminates our days even longer, the world is full of beautiful new blooms, the birds are chirping, and it seems that everything is truly “new” again. So for this week’s blog, I thought that this would be a perfect time to look back at 2018 and really take in all that happened across the U.S. weather-wise.

The average precipitation in 2018 was 4.69 inches above average, making it the wettest in the past 35 years, and third wettest since the modern record began in 1895. This total was largely driven by record and near-record annual precipitation across much of the eastern United States stretching from the nation’s Corn Belt to North Carolina, including Washington D.C., Baltimore, and Pittsburgh. In part thanks to Hurricane Florence, the rainfall in Wilmington, North Carolina surpassed 100 inches, more than three feet above normal!

Did you know?

  • Tennessee, North Carolina, Virginia, West Virginia, Maryland, Delaware, New Jersey, and Massachusetts had their wettest years on record.
  • In June, flash flooding hit parts of Michigan, Minnesota, and Wisconsin. Highways were washed out, and rivers set record crests.
  • Puerto Rico was characterized by below average precipitation.
  • During a 24-hour period spanning April 14-15, 2018, a rain gauge at Waipā Garden, near Hanalei, on the Hawaiian island of Kauai, observed 49.69 inches of rainfall! This is the greatest verified amount of precipitation observed in 24 hours in the United States. The previous record of 43 inches was set at Alvin, Texas, in July 1979.
A bicyclist rides through a flooded South Water Street on Friday as Florence makes landfall in Wilmington, N.C. MUST CREDIT: Washington Post photo by Ricky Carioti

Summer (June through August) of 2018 tied with 1934 as the fourth hottest summer on record for the contiguous United States. The nationally average minimum temperature (overnight lows) was exceptionally warm over the summer at 60.9°F, 2.5°F above average and 0.1°F warmer than the previous record set in 2016! Looking at the entire year, much of the United States was warmer than average, particularly west of the Rockies and across the coastal south-east, which were characterized by much-above-average temperatures. This means that their temperatures were within 10% of the record. The average annual temperature for the contiguous U.S. was 53.5°F, 1.5°F above the 20th century average. This was the 14th warmest year on record and made 2018 the 22nd consecutive warmer-than-average year for the U.S. (1997 through 2018). The daily minimum temperatures were the seventh highest on record, with this effect being felt the most in portions of the East, Midwest, and Plains. North Carolina and Virginia both observed the highest average overnight temperatures of their respective records.

A map from the National Oceanic and Atmospheric Administration shows how 2018 temperatures throughout the U.S. compared to average temperatures in the 20th century.

Did you know?

  • The last four-year (2015–2018) and five-year (2014–2018) periods are the warmest four- and five-year stretches on record for the contiguous U.S.
  • Since 1895, the contiguous U.S. has observed an average temperature increase of 1.5°F per century.
  • Outside the contiguous U.S., Alaska’s statewide temperature of 30.4°F, which is 4.5°F warmer than its long-term (1925–2000) average, made 2018 its second warmest year on record, behind only 2016. Record low sea ice plagued parts of western and northern Alaska early in the year, contributing to its above average temperatures
    • The Alaska annual temperature is increasing at an average rate of 2.9°F per century since 1925!

Notable Extremes and Events of 2018

There were 14 weather and climate related disasters with losses each exceeding $1 billion during 2018. These disasters included two tropical cyclones (Hurricanes Florence and Michael), one western wildfire disaster that included several constituent wildfires over several months, eight instances of severe convective storms (hail, tornado, and/or damaging winds), one large drought episode, and two winter storms. The 14 events claimed at least 247 lives and had total losses estimated at $91 billion. Approximately $73 billion of this total is attributed to Hurricane Michael ($25 billion), Hurricane Florence ($24 billion), and the complex of western wildfires ($24 billion).

2018 marked the eighth consecutive year with eight or more billion dollar disasters, exceeding the long-term average of 6.2 per year. It was also the eighth year overall with at least 10 billion-dollar disasters; all but one of those years have occurred since 2008. The U.S. Climate Extremes Index (USCEI) is an index that tracks extremes (falling in the upper or lower 10 percent of the record) in temperature, precipitation, drought and land falling tropical cyclones across the contiguous U.S. For 2018, the USCEI was 66% above average and ranked as the eighth highest annual USCEI in the 109-year period. When excluding the tropical cyclone component, the USCEI remained 66% above average and ranked as the ninth highest on record. Extremes in warm minimum temperatures (fifth highest) and days with precipitation (highest) contributed to the elevated USCEI.

A Closer look at three 2018 Disasters

  • Two large and devastating wildfires impacted California in early November. The Camp Fire burned more than 153,000 acres in Northern California, near Chico. The fire caused at least 88 fatalities and destroyed more than 18,000 structures, with the town of Paradise being the hardest hit. This marked the most destructive and deadliest wildfire on record in California and the deadliest wildfire in the U.S. since the Cloquet Fire in 1918 killed 453 people in Minnesota. In Southern California, the Woolsey Fire destroyed more than 1,500 structures and caused at least three fatalities in and around Malibu.
  • Hurricane Michael made landfall near Mexico Beach, Florida, on October 10th with sustained winds of 155 mph. This was the third most intense hurricane to make landfall in the contiguous U.S. based on central pressure and the fourth most intense based on wind speed. Michael was also the most intense hurricane on record to make landfall along the Florida Panhandle. The storm caused widespread devastation across the Florida Panhandle and farther inland across Georgia, the Carolinas and Virginia. There were at least 45 fatalities blamed on the storm in the U.S.
  • Hurricane Florence, one of the deadliest and costliest to ever impact the Carolinas, made landfall near Wrightsville Beach, NC, on September 14th and moved inland slowly, with heavy rains, storm surge and record flooding, causing at least 51 deaths and extensive flooding across much of the Carolinas and Virginia.
Camp Fire. Photo courtesy Berkeley Firefighters

According to the U.S. National Climate Assessment, the rise of extreme events like wildfires, floods, and tropical cyclones pose immediate danger to public health and well-being. The changing environment is expected to cause more heat stress, an increase in waterborne diseases, poor air quality, and diseases transmitted by insects and rodents. Extreme weather events can compound many of these health threats. Our food supply also depends on climate and weather conditions. Although agricultural practices may be adaptable, changes like increased temperatures, water stress, diseases, and weather extremes create challenges for the farmers and ranchers who put food on our tables. However, the report makes clear that many local and state governments are taking action to lower their own carbon emissions and cope with climate impacts. The changes and choices we make today can make a big difference for our future. Individuals, businesses, and communities of all sizes can use the U.S. Climate Resilience Toolkit to discover and document climate hazards in their location, and then then develop workable solutions to build resilience and lower climate-related risks.

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