Climate Matters•November 13, 2024
2024 Winter Package
KEY CONCEPTS
Meteorological winter, which starts December 1, 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 235 U.S. locations from 1970 to 2024 — by 4°F on average.
Warm winter days now happen more often. About 87% 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.
This Climate Matters analysis was made possible by open access data from NOAA/NCEI.
Winter is warming in 235 U.S. cities
Climate Central analyzed winter average temperature data from 241 U.S. locations (see Methodology) to see how and where winters have warmed from 1970 to 2024:
Average winter temperatures increased in 235 (98%) locations since 1970.
Over that period, the average winter warming across these 235 locations was 4°F.
Average winter temperatures warmed by 2°F or more in 212 (88%) of locations.
Winter warmed the most, on average, in locations across the Upper Midwest (5.5°F), Northeast (5°F), and Ohio Valley (4.6°F).
The top winter warming locations were: Burlington, Vt. (8.2°F); Milwaukee, Wis. (7.4°F); Concord, N.H. (7°F); Green Bay, Wis. (7°F); and Albany, N.Y. (6.8°F); and Toledo, Ohio (6.8°F).
More warmer-than-normal winter days
The warming season is also reflected in the growing number of winter days that are warmer than the 1991-2020 winter normal temperature for that location.
Since 1970, the average number of warmer-than-normal winter days has increased in 231 (96%) of the 241 locations analyzed.
The majority of locations (87%, or 210) 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 (18 more days on average) and Upper Midwest (17 more days on average).
The cities that saw the largest increase in warmer-than-normal winter days since 1970 were: Las Vegas (31 more days) and San Francisco (29 more days).
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 246 U.S. locations analyzed by Climate Central.
Locations across the Northeast and the Great Lakes region have seen some of the highest rates of winter warming since 1970.
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 2024.
The average change across these 204 locations was 13 fewer freezing nights.
There are still cold streaks in a warming world — but shorter ones.
Winter’s longest cold streaks have gotten shorter since 1970 in 98% (236) of 240 U.S. locations analyzed.
Winter cold streaks are now six days shorter, on average, across these 240 U.S. locations.
There are still extremely cold days in a warming world — but not as cold.
From 1970 to 2024, the coldest day of the year has warmed by 7°F on average across 242 U.S. locations analyzed by Climate Central.
A rise of at least 10°F was recorded in 50 locations — one-third of which were located in the Ohio Valley.
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 (methane 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 the fall.
snow and ice. Warming winters can affect the timing, location, and amount of snowfall and the coverage and duration of Great Lakes 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
According to NOAA’s U.S. winter outlook, the country’s northern tier is likely to be wetter-than-average while the southern tier, eastern Great Lakes, New England, and the eastern seaboard are likely to see a warmer-than-normal winter.
With La Niña developing and favored to emerge later this fall, the winter outlook is broadly consistent with typical winter La Niña patterns in the U.S.
LOCAL STORY ANGLES
Winter storm severity and impacts:
According to Climate Central analysis, nearly one-quarter (23%) of the 1,755 weather-related power outages between 2000-2023 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 with 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 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 2023-24 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. For reported data summaries based on linear trends, however, only 241 stations are included due to data completeness measures that were not met by six stations: Bend, Ore.; Dothan, Ala.; Hattiesburg, Miss., Hazard, Ky; Panama City, Fla.; and Wheeling, W.Va.