December Was Warmest On Record

The year 2021 was marked by extremes across the U.S., including exceptional warmth, devastating severe weather and the second-highest number of billion-dollar weather and climate disasters on record.

The nation also saw an active wildfire year across the West as the north Atlantic Basin stayed busy with its third most-active Atlantic hurricane season on record, according to scientists from NOAA’s National Centers for Environmental Information.

Here’s a recap of the climate and extreme weather events across the U.S. in 2021:

Climate by the numbers

December 2021 | Full year 2021 

The December contiguous U.S. temperature was 39.3 degrees F, 6.7 degrees above average, making it the warmest December on record and exceeding the previous warmest December in 2015.

Ten states — Alabama, Arkansas, Kansas, Louisiana, Mississippi, Missouri, Nebraska, New Mexico, Oklahoma and Texas — also had their warmest Decembers on record.

For 2021, the average contiguous U.S. temperature was 54.5 degrees F, 2.5 degrees above the 20th-century average and ranked as the fourth-warmest year in the 127-year period of record. The six warmest years on record have all occurred since 2012.

Maine and New Hampshire had their second-warmest year on record with 19 additional states across the Northeast, Great Lakes, Plains and West experiencing a top-five warmest year. Meanwhile, Alaska’s average annual temperature was 26.4 degrees F, 0.4 of a degree above the long-term average and the coldest year since 2012.

Precipitation across the contiguous U.S. totaled 30.48 inches (0.54 of an inch above average), which placed 2021 in the middle third of the climate record. Massachusetts had its ninth-wettest year on record, while Montana ranked ninth driest on record for 2021.

According to the U.S. Drought Monitor, drought coverage remained fairly significant and steady throughout much of 2021, with a minimum extent of 43.4% occurring on May 25 and maximum coverage of 55.5% on December 7.

Billion-dollar disasters in 2021

Last year, the U.S. experienced 20 separate billion-dollar weather and climate disasters that killed at least 688 people — the most disaster-related fatalities for the contiguous U.S. since 2011 and more than double last year’s number of 262. The following 20 events, each exceeding $1 billion, put 2021 in second place for the highest number of disasters recorded in a calendar year, behind the record 22 separate billion-dollar events in 2020:

• 1 winter storm/cold wave event (focused across the deep south and Texas).
• 1 wildfire event (western wildfires across Arizona, California, Colorado, Idaho, Montana, Oregon and Washington).
• 1 drought and heat wave event (summer/fall across western U.S.).
• 2 flood events (in California and Louisiana).
• 3 tornado outbreaks (including the December tornado outbreaks).
• 4 tropical cyclones (Elsa, Fred, Ida and Nicholas).
• 8 severe weather events (across many parts of the country, including the December Midwest derecho).

Damages from these disasters totaled approximately $145 billion for all 20 events. This exceeds the total damage of $102 billion from the 22 events in 2020.

Hurricane Ida was the most costly event of 2021 at $75 billion and ranks among the top-five most costly hurricanes on record (since 1980) for the U.S. The combined cost of the four tropical systems was approximately $78.5 billion, more than 54% of the total U.S. billion-dollar disaster price tag in 2021.

The historic mid-February winter storm/cold wave was the costliest winter storm on record ($24 billion), more than double the previous record winter storm event — the Storm of the Century in March 1993.

The total cost over the last five years of these disasters (2017-2021) exceeds $742 billion — averaging $148 billion a year. These five-year and annual average costs both set record highs.