Assessing the U.S. Climate in 2017

https://www.ncei.noaa.gov/news/national-climate-201712?position=1&list=YUifwFUJzIcmYCx11e6F8_vooKFgXHw55fyBhPtRgtc

Based on preliminary analysis, the average annual temperature for the contiguous U.S. was 54.6°F, 2.6°F above the 20th century average. This was the third warmest year since record keeping began in 1895, behind 2012 (55.3°F) and 2016 (54.9°F), and the 21st consecutive warmer-than-average year for the U.S. (1997 through 2017). The five warmest years on record for the contiguous U.S. have all occurred since 2006.

During the year, the U.S. experienced 16 weather and climate disasters with losses exceeding $1 billion, with total costs of approximately $306 billion – a new U.S. annual record. The previous costliest year for the U.S. was 2005 with losses of $215 billion driven in large part by Hurricanes Katrina, Wilma and Rita. The number of events (16) ties 2011 for most billion-dollar disasters in a single year. Some of the more noteworthy events included the western wildfire season, with total costs of $18 billion, tripling the previous U.S. annual wildfire cost record. Hurricane Harvey had total costs of $125 billion, second only to Hurricane Katrina in the 38-year period of record for billion-dollar disasters. Hurricanes Maria and Irma had total costs of $90 billion and $50 billion, respectively. Hurricane Maria now ranks as the third costliest weather and climate disaster on record for the nation and Irma ranks as the fifth costliest.

•••••

For the third consecutive year, every state across the contiguous U.S. and Alaska had an above-average annual temperature. Despite cold seasons in various regions throughout the year, above-average temperatures, often record breaking, during other parts of the year more than offset any seasonal cool conditions.

Five states – Arizona, Georgia, New Mexico, North Carolina and South Carolina – had their warmest year on record. Thirty-two additional states, including Alaska, had annual temperatures that ranked among the 10 warmest on record.

•••••

The U.S. Climate Extremes Index (USCEI) for 2017 was the second highest value in the 108-year period record at more than double the average. Only 2012 had a higher USCEI value. On the national scale, extremes in warm maximum and minimum temperatures, one-day precipitation totals, days with precipitation and landfalling tropical cyclones contributed to the elevated USCEI. The USCEI is an index that tracks extremes (falling in the upper or lower 10 percent of the record) in temperature, precipitation, drought and landfalling tropical cyclones across the contiguous U.S.

There were a record-tying 16 weather and climate disasters with losses exceeding $1 billion during 2017 including three tropical cyclones, eight severe storms, two inland floods, a crop freeze, drought and wildfires causing a total of 362 direct fatalities among these events. However, 2017 arguably has more events than 2011 given that our analysis traditionally counts all U.S. billion-dollar wildfires as a single, seasonal event. In the 38-year period of record, the U.S. has sustained 219 weather and climate disasters where the overall damage costs reached or exceeded $1 billion. The cumulative costs for these 219 events exceed $1.5 trillion.

•••••