The holidays are warming, and human-induced climate change is in the driver’s seat. Across the United States, thermometers are climbing ever higher in late November, in many places making Thanksgiving feel like it’s occurring two or three weeks earlier.

Last November was the second-warmest globally on record, according to the National Centers for Environmental Information, falling just behind 2015. Some organizations, such as NASA and the European Copernicus Climate Change Service, assert that 2020 took the top spot.

The observations lay bare the unmistakable rise in global temperatures as climate change continues. The planet has seen a litany of climate-fueled disasters this year, the product of natural variability supercharged by our warming world.

Thanksgiving by the numbers

While global warming is, by virtue of being a planetary-scale phenomenon, global, its impacts are realized on a local level. We crunched the numbers and found that virtually every city in the Lower 48 is warming markedly during the period surrounding Thanksgiving (Nov. 22-28), in many cases outpacing average fall, November or annual warming.

In Philadelphia, for instance, the week of Nov. 22 to 28 has warmed nearly 4 degrees since 1950. That may not sound like much, but it’s the equivalent of Thanksgiving shifting two weeks earlier in the years during that interim. A number of cities, notably Minneapolis, St. Louis and Miami, are warming even more quickly. Thanksgiving week in Phoenix has heated up half a dozen degrees since 1950.

What it means

The rising temperatures mean not only milder Thanksgiving weather but also altered precipitation.

Each degree increase in air temperature corresponds to a 4 percent uptick in the atmosphere’s ability to carry moisture.

In the West, where moisture is tougher to come by, the warmer environment means drier conditions as the ground becomes sapped of its humidity. That can lend itself to more severe wildfire seasons that linger longer into the autumn. Just last week, a wildfire cropped in the mountains west of Denver.

A serious threat of wildfires currently encompasses Southern California, which has seen abnormally warm and dry conditions in recent weeks.

Across the southern and southeastern United States, the warming conditions would ordinarily translate to more humidity and rainfall. We found little to no change in Thanksgiving-week precipitation totals in most spots, however.

There’s a chance that, as warmer conditions build farther north, and as the north-to-south temperature gradient, or steepest change in temperature with horizontal distance, shifts north, the axis of heaviest precipitation is following it. That could offset any increase in moisture availability associated with the warmer temperatures.

There are some reasons to believe that climate change, which is warming the waters off New England and the Northeast, may be contributing to an increase in cold-season severe weather and tornado activity there. Warming conditions fuel taller and stronger thunderstorms, which can tap into seasonably strong winds aloft and quickly become problematic. On Nov. 13, nearly a dozen tornadoes plowed across Long Island, Connecticut and Rhode Island.

How much has it warmed by?

We looked at data from 20 cities across the contiguous United States and Alaska, running the numbers to see how much each city was warming per decade. Of the cities we surveyed, every city recorded a noticeable increase in temperature, and some were warming at a breakneck pace.

See how your city is changing over time:

  • Washington, D.C. Warming
    • 0.55 degrees per decade
    • 3.9 degrees since 1950
  • Boston Warming
    • 0.32 degrees per decade
    • 2.3 degrees since 1950
  • Philadelphia Warming
    • 0.55 degrees per decade
    • 3.9 degrees since 1950
  • Hartford, Conn. Warming
    • 0.36 degrees per decade
    • 2.6 degrees since 1950
  • Raleigh, N.C. Warming
    • 0.54 degrees per decade
    • 3.8 degrees since 1950
  • Atlanta Warming
    • 0.80 degrees per decade
    • 5.7 degrees since 1950
  • Orlando Warming
    • 0.29 degrees per decade
    • 2.1 degrees since 1950
  • Miami Warming
    • 0.65 degrees per decade
    • 4.6 degrees since 1950
  • Huntsville, Ala. Warming
    • 0.56 degrees per decade
    • 4.0 degrees since 1950
  • Dallas (Love Field) Warming
    • 0.47 degrees per decade
    • 3.3 degrees since 1950
  • Oklahoma City Warming
    • 0.33 degrees per decade
    • 2.3 degrees since 1950
  • St. Louis Warming
    • 0.82 degrees per decade
    • 5.8 degrees since 1950
  • Chicago Warming
    • 0.17 degrees per decade
    • 1.2 degrees since 1950
  • Minneapolis Warming
    • 0.78 degrees per decade
    • 5.5 degrees since 1950
  • Bismarck, N.D. Warming
    • 0.37 degrees per decade
    • 2.6 degrees since 1950
  • Phoenix Warming
    • 0.86 degrees per decade
    • 6.1 degrees since 1950
  • Los Angeles Warming
    • 0.40 degrees per decade
    • 2.8 degrees since 1950
  • San Francisco Warming
    • 0.28 degrees per decade
    • 2.0 degrees since 1950
  • Seattle Warming
    • 0.05 degrees per decade
    • 0.4 degrees since 1950
  • Anchorage Warming
    • 0.57 degrees per decade
    • 4.0 degrees since 1950

The warming observed in these cities is probably due to the increasing concentrations of heat-trapping gases in the atmosphere from fossil fuel burning, as well as urbanization.

The big picture

Autumn is commonly regarded as an overlooked season in climate change research. Shifting animal migration and vegetation patterns are just some of the many byproducts of the warming temperatures, as are increased fire danger in the West and a shift in the timing of peak fall foliage in the Northeast. Agricultural and economic consequences will follow suit.

Warming is also particularly prevalent around the December holidays, especially in the Mid-Atlantic. It may be the product of both coincidence and some legitimate phenomenon that favors that time of year for extra-speedy warming. But, regardless of the specifics, one thing is clear: Human-caused climate change is warming the planet, and it’s hitting home.