We are now three weeks into the new year, and it seems like a great time to take a look back at the last year. Though it was notable in innumerable ways, we want to focus on the significant weather events and climate anomalies of 2020.
Temperature Trends and Rankings
Unsurprisingly, 2020 was hot. How hot? The average annual temperature of the contiguous US was 2.4 degrees Fahrenheit above average, ranking 2020 as the fifth-warmest year in the 126-year record. Not only as an average across the US though…each individual state recorded temperatures above or much above average. There was not a single state that recorded near average or below average temperatures. Ten states across the Southwest, Southeast and East Coast had their second-warmest year on record.
Both the nationally average maximum temperature and nationally averaged minimum temperature were above average as well. Arizona’s maximum temperatures were the highest on record and seven states (Alabama, South Carolina, North Carolina, Virginia, West Virginia, Maryland and Delaware) recorded their warmest ever minimum temperatures. Influenced by warm ocean temperatures, Kahului and Hilo (Hawaii) experienced a record-warm year in 2020.
For the year, warm daily records outpaced cold records by a margin of approximately two to one. There were over 106,000 daily temperature records tied or broken during 2020.
Precipitation: A Nation Divided
As a whole, the contiguous United States average annual precipitation was 30.28 inches (0.34 inches above the long-term average), which ranks in the middle third of the historical record. Middle of the pack seems normal, right? As a whole, definitely…which is why we need to take a look at individual states.
Above-average annual precipitation was observed from the Plains into the Great Lakes and Southeast into the Mid-Atlantic regions. North Carolina had its second-wettest year on record, and Virginia had its third-wettest. Conversely, our friends on the West Coast, Southwest and Northern Rockies were observing some of their driest years ever. Nevada and Utah ranked driest on record for 2020 with Colorado and Arizona ranking second driest. How much drier was it this year? Utah’s 7.23 inches of annual precipitation was 0.89 inches less than the previous record set in 1956.
Drought coverage expanded throughout much of 2020 with a minimum CONUS (continental US) extent of 9.6 percent occurring on February 18 and maximum coverage of approximately 50 percent on December 22. On December 29, extreme and exceptional drought (the two highest rankings) covered approximately 22% of the continental United States – the largest coverage since August 2012.
Billion-Dollar Weather and Climate Disasters
In 2020, there were 22 weather and climate disaster events with losses exceeding $1 billion each across the United States. TWENTY-TWO. This shatters the previous record (16) that occurred in 2011 and 2017. Annual losses in 2020 exceed $95 billion, the fourth highest on record. Let’s take a closer look at the numbers.
- The 22 events this year included: Seven tropical cyclone events, 13 severe storm events, one drought and one wildfire event.
- Most costly events: Hurricane Laura, the Western wildfires and the Midwest derecho.
- The seven tropical cyclone disasters broke the old record of four separate billion-dollar tropical cyclones which occurred in both 2004 and 2005.
- The Midwest derecho produced damage costs of $11 billion. The historic severe weather event’s damage to infrastructure and crops made it only the third-ever severe weather event with costs over $10 billion
- The total cost of U.S. billion-dollar disasters over the last five years (2016-2020) exceeds $600 billion.
- 2020 also marks the sixth consecutive year (2015-20) in which 10 or more separate billion-dollar disaster events have impacted the U.S.
(Note: Our June blog took a look at the climate halfway through the year and gives an in-depth description of Billion-Dollar Weather and Climate Disasters.)
- Thirty named storms formed in the Atlantic, which breaks the previous record of 28 set in 2005. The 13 hurricanes and six major hurricanes in 2020 are both the second most on record behind 2005 (15 and 7, respectively).
- Twelve named U.S. storm continental landfalls occurred during 2020. This breaks the previous annual record of nine landfalls set in 1916.
- Six hurricanes made U.S. landfall, tying 1886 and 1985 for the most U.S. hurricane landfalls in a single season.
- Five named storms (Cristobal, Marco, Laura, Delta and Zeta) made landfall in Louisiana in 2020, which is the most on record for any state in one year.
- On September 14, five tropical cyclones were active at the same time in the Atlantic. This ties September 1971 for the most storms to be active at once on record.
- Category 5 Hurricane Iota formed during November and was the most intense Atlantic hurricane of the season. It was also the second-strongest November hurricane on record for the Atlantic and was the strongest Atlantic hurricane on record to occur so late in the calendar year.
- This was a record fifth consecutive year with at least one Category 5 storm in the Atlantic.
- Five Category 4 and 5 storms formed in the Atlantic during 2020, tying with 1933, 1961, 1999 and 2005 for the record.
2020 was the most active wildfire year on record (1983 to present) across the West. Nearly 10.3 million acres were consumed during 2020, exceeding the 2000-2010 average by 51 percent. This was the largest acreage consumed in the U.S. since at least 2000.
- The three largest wildfires in Colorado history occurred during 2020: The Cameron Peak Fire, the East Troublesome Fire and the Pine Gulch Fire each exceeded the acreage burned by the previous record, the 2002 Hayman Fire.
- Approximately four percent of California’s nearly 100 million acres were consumed by wildfires in 2020, which is the largest wildfire season on record for the state. Five of the six largest wildfires in California history also occurred during 2020. Over 4.3 million acres burned across California during 2020.
- With many of these large fires burning simultaneously, heavy smoke and poor air quality impacted many of the western states and Canada over many days during September.
- Wildfire activity across Alaska was below average and consumed approximately 181,000 acres in 2020 — only 15 percent of the 2010-2019 average.
Other Notable Extremes
Boulder, Colorado experienced its snowiest season on record with 152 inches of snow. Caribou, Maine also had significant snow during the 2019-2020 season receiving 146 inches and ranked ninth highest for any season on record.
The number of tornadoes (approximately 1,200) in 2020 was slightly lower than normal , with the most notable outbreak occurring April 12-13 when at least 140 tornadoes occurred from Texas to Maryland leading to 32 tornado-related fatalities. This was the deadliest tornado outbreak across the U.S. since April 27-30, 2014. No EF-5 tornadoes were reported during 2020. The most recent tornado classified as an EF-5 occurred in 2013.
The U.S. Climate Extremes Index (USCEI) for 2020 was 80 percent above average and ranked as seventh highest in the 111-year record. 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.
For a more detailed look into specific regions of the United States, please visit https://www.ncdc.noaa.gov/sotc/national/202013. For a look at the Global Climate Report for 2020, please visit https://www.ncdc.noaa.gov/sotc/global/202013 (spoiler alert: 2020 was the second-warmest year on record globally).
Earth’s climate is now changing faster than at any point in the history of modern civilization, and while the impacts of climate change are already being felt in the United States, they are projected to intensify in the future. Climate-related risks will certainly continue to grow without additional action. However, we can take actions today that will reduce those impacts.