Climate Matters•November 22, 2023
2023 Winter Package
KEY CONCEPTS
Meteorological winter starts December 1, and is the fastest-warming season for most of the U.S. — affecting snowfall, water supplies, winter sports, spring allergies, summer fruits, and more.
Winters have warmed in 233 U.S. locations from 1970 to 2022 — by 3.8°F on average.
Warm winter days now happen more often. About 84% of locations now have at least seven more winter days above normal than in 1970.
In our warming world the coldest days aren’t as cold, and cold snaps are shrinking.
Warming winters affect public health, water supplies, agriculture, and recreation.
Download data:
Holiday graphics: November temperature trends and Thanksgiving extremes
Climate Central analyzed November temperature trends in 241 U.S. locations from 1970 to 2022.
Most locations (82%, or 205) saw November temperatures rise during that period — by 2.1°F on average.
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Winter is warming — fast.
The most rapid warming in the U.S. has generally occurred when and where it’s coldest, including at night, in northern parts of the country—and during winter.
Winter (December, January, February) is the fastest warming season for the majority (74%) of U.S. locations analyzed by Climate Central.
Locations with the fastest winter warming since 1970 are found from coast to coast, but especially in the Northeast and the Great Lakes region.
Winter is warming in 233 U.S. cities
Climate Central analyzed winter average temperature data from 240 U.S. locations (see Methodology) to see how and where winters have warmed from 1970 to 2022:
Average winter temperatures increased in 233 (97%) of locations since 1970.
Over that period, the average winter warming across these 233 locations was 3.8°F.
Average winter temperatures warmed by 2°F or more in 206 (86%) of locations.
Winter warmed the most, on average, in locations across the Upper Midwest (4.7°F), Northeast (4.6°F), and Ohio Valley (4.3°F).
The top-five winter warming locations were: Burlington, Vt. (7.7°F), Albany, Ga. (7°F), Chattanooga, Tenn. (6.7°F), Milwaukee, Wis. (6.7°F), and Concord, N.H. (6.6°F).
More warmer-than-normal winter days
The warming season is also reflected in the growing number of winter days with temperatures above the 1991-2020 winter normal temperature for that location.
Since 1970, the average number of warmer-than-normal winter days has increased in 229 (95%) of the 240 locations analyzed.
The majority of locations (84%, or 202) now experience at least seven more warmer-than-normal winter days than they did in 1970.
The rise in warmer-than-normal winter days was highest among locations in the Northeast (16 more days on average) and Upper Midwest (14 more days on average).
The cities that saw the largest increase in warmer-than-normal winter days since 1970 were: Las Vegas, Nev. (30 more days), Honolulu, Hawai’i (27 more days), and San Francisco, Ca. (27 more days).
There are still freezing nights in a warming world — but fewer of them.
The annual number of freezing nights has dropped in 204 U.S. locations from 1970 to 2022.
The average change across these 204 locations was 13 fewer freezing nights.
There are still cold spells in a warming world — but shorter ones.
From 1970 to 2021, 97% of 244 U.S. locations analyzed experienced shrinking winter cold snaps.
Cold snaps shrank by 6 days on average across all 244 stations from 1970 to 2021.
There are still extremely cold days in a warming world — but not as cold.
From 1970 to 2020, annual minimum temperatures warmed by at least 1°F in 98% of 244 U.S. locations.
The average trend across these cities was a 7°F rise, and 42 cities recorded an increase of 10°F or more in their annual lowest temperature.
Winter warming affects…
western water supplies. Warming winters can reduce mountain snowpack — a critical source of spring meltwater that refills reservoirs, irrigates crops, and helps meet peak water demand across the western U.S. during summer.
energy use in homes. Warming winters have contributed to decreasing trends in heating degree days and residential natural gas use since 1974. But winter energy savings may be offset by increased cooling demand already reflected in a near-doubling of per capita summer residential electricity use since 1973.
summer fruit. Warmer, shorter winters can disrupt the chill that fruit and nut crops — a nearly $27 billion industry in the U.S. — depend on. Climate Central analysis found that winter chill has decreased in 84% of 215 locations, including in counties that grow the 10 most valuable fruit and nut crops (especially in California, Washington, Florida, Oregon, South Carolina, and Georgia).
disease-carrying pests. Cold winters can keep the populations of disease-carrying pests like mosquitoes in check. But warmer, shorter winters can worsen pest-related health risks.
growing seasons and allergies. Warmer, shorter winters mean earlier spring thaw and later fall freeze — giving plants more time to grow and release allergy-inducing pollen earlier in spring and later into fall.
snow and ice. Warming winters can affect the timing, location, and amount of snowfall and the coverage and duration of lake ice — with a range of impacts for people, ecosystems, and water supplies in different regions of the U.S.
winter sports and recreation. The multi-billion dollar winter recreation industry could take an economic hit because of rising temperatures and reduced snow and ice accumulation. February temperatures in the 19 cities to host the Winter Olympics since 1950 have warmed by 4.8 °F on average since 1950.
Winter Outlook
El Niño conditions are projected to continue through winter 2023-2024. Historically, El Niño winters have been associated with warmer-than-normal winter temperatures across the northern U.S.
According to NOAA’s U.S. winter outlook, the western and southeastern regions are likely to experience wetter-than-average conditions while parts of the northern Rockies and Upper Midwest regions are likely to experience drier-than-average winter conditions.
LOCAL STORY ANGLES
Winter storm severity and impacts:
According to Climate Central analysis, 22% of the 1,542 weather-related power outages between 2000-2021 were caused by winter weather. NOAA offers interactive tools to track the potential disruptions and hazards due to severe winter weather. NOAA’s new Experimental Probabilistic Winter Storm Severity Index maps the likelihood of different local impacts from expected winter hazards over a 7-day period. The companion Winter Storm Severity Index maps the potential severity of winter storms over a 3-day period.
Tools for reporting on local winter weather:
Warmer temperatures can make winter storms more hazardous, with sleet and freezing rain. Criteria for winter storm watches, advisories, and warnings can vary by region so check out your local National Weather Service office. The NWS also provides helpful information on how to stay safe in winter conditions, wind chill charts, and an explanation of the polar vortex. The National Weather Service’s Winter Page provides maps and forecasts for snow and ice in your area. Their Winter Weather Desk provides twice-daily local forecasts for snow and freezing rain.
FIND EXPERTS
Submit a request to SciLine from the American Association for the Advancement of Science or to the Climate Data Concierge from Columbia University. These free services rapidly connect journalists to relevant scientific experts.
Browse maps of climate experts and services at regional NOAA, USDA, and Department of the Interior offices.
Explore databases such as 500 Women Scientists, BIPOC Climate and Energy Justice PhDs, and Diverse Sources to find and amplify diverse expert voices.
Reach out to your State Climate Office or the nearest Land-Grant University to connect with scientists, educators, and extension staff in your local area.
METHODOLOGY
Average temperatures and days above normal were calculated for each winter (December, January, February) from 1969-70 to 2022-23 using data obtained from the Applied Climate Information System. Winter days above normal are defined as the number of days where the average temperature was above the 1991-2020 NOAA/NCEI climate normal. Climate Central's local analyses include 247 stations. However, for reported data summaries based on linear trends, only 240 stations are included due to data completeness measures that were not met by seven stations: Bend, Ore.; Dothan, Ala.; Hattiesburg, Miss., Hazard, Ky; Panama City, Fla.; Terre Haute, Ind.; and Wheeling, W.Va.
November average temperatures from 1970-2022 were retrieved from the Applied Climate Information System (ACIS). Local Thanksgiving climate extremes were also retrieved from ACIS, but included each station’s entire period of record (POR). Climate Central's November/Thanksgiving analysis included 247 stations. Only 241 stations were included in reported data summaries based on linear trends, however, completeness measures that were not met by six stations: Dothan, Ala.; Hattiesburg, Miss., Hazard, Ky; Terre Haute, Ind.; Twin Falls, Idaho; and Wheeling, W.Va.
Detailed methodology and complete graphics sets for analysis of annual number of coldest nights, winter cold snap trends, and of annual minimum temperature trends are included in the hyperlinked releases.