America’s Warmest Major Cities in December

December marks the beginning of the meteorological winter, and in the United States, it is one of the coldest months of the year. Between 1901 and 2000, the average temperature across the Lower 48 during the month of December was just 32.7°F – only 2.6°F higher than the 20th century average temperature in January, the coldest month in the United States. So far, December 2025 is off to an especially cold start. 

In the first week of the month this year, Arctic air is expected to move south from Canada and bring record cold to millions of Americans across the Midwest and Northeast. In the northern Great Plains, temperatures are expected to fall below zero, impacting major population centers. Record-breaking lows are also expected in Des Moines, Iowa, and Pittsburgh, as well as parts of Missouri and Ohio. Even in states as far south as Oklahoma and Texas, temperatures are expected to dip into the 20s. By the end of the week, frigid temperatures will have spread to the Northeast, impacting parts of New York and New England before an anticipated second shot of frigid air will push the mercury below zero in parts of Minnesota, North Dakota, and Wisconsin. 

But while the looming cold front will likely be historic, all Americans – regardless of where they live – can generally expect temperatures to fall throughout December. Still, there are many parts of the country where the first month of winter is usually mild, or even warm. In major population centers across the Southern and Western United States, daily highs in the 60s or 70s are the expected norm in December.

Using data from the National Oceanic and Atmospheric Administration, Climate Crisis 247 identified the warmest major American cities in the month of December. We reviewed historical data for over 200 places in the continental U.S. and ranked them on their average temperature in the month of December between 1991 and 2020. Only cities with populations of at least 250,000, and where average December temperatures are above 55°F appear on this list. Supplemental data on the warmest December on record in these places is also from NOAA. Population data are five-year estimates from the U.S. Census Bureau’s 2023 American Community Survey. Cities are ranked based on their average historical temperature in the month of December. 

Among 10 the cities on this list – which collectively are home to nearly 12 million people – average December temperatures range from 56.5°F up to 71.3°F. These cities are spread across five states: Arizona, California, Florida, Louisiana, and Texas. 

While these places have long been relatively warm throughout the month, climate change appears to be pushing temperatures even higher in recent years. Each of these places have had Decembers in which average temperatures exceeded the baseline monthly average by several degrees, in most cases, by at least 5°F. Notably, in all but one of these cities, the warmest December on record was reported in 2015 or later. 

10. New Orleans, Louisiana

• Average December temperature in New Orleans, 1990-2020: 56.5°F
• Warmest December on record in New Orleans: 2021 (65.6°F avg. temp.)
• Local population: 376,035

9. San Diego, California

• Average December temperature in San Diego, 1990-2020: 56.6°F
• Warmest December on record in San Diego: 1940 (59.8°F avg. temp.)
• Local population: 1,385,061

8. Los Angeles, California

• Average December temperature in Los Angeles, 1990-2020: 56.9°F
• Warmest December on record in Los Angeles: 2023 (60.8°F avg. temp.)
• Local population: 3,857,897

7. Jacksonville, Florida

• Average December temperature in Jacksonville, 1990-2020: 57.1°F
• Warmest December on record in Jacksonville: 2015 (67.0°F avg. temp.)
• Local population: 961,739

6. Phoenix, Arizona

• Average December temperature in Phoenix, 1990-2020: 57.2°F
• Warmest December on record in Phoenix: 2024 (62.3°F avg. temp.)
• Local population: 1,624,832

5. Houston, Texas

• Average December temperature in Houston, 1990-2020: 57.3°F
• Warmest December on record in Houston: 2021 (69.2°F avg. temp.)
• Local population: 2,300,419

4. Corpus Christi, Texas

• Average December temperature in Corpus Christi, 1990-2020: 59.3°F
• Warmest December on record in Corpus Christi: 2021 (68.8°F avg. temp.)
• Local population: 317,383

3. Orlando, Florida

• Average December temperature in Orlando, 1990-2020: 64.0°F
• Warmest December on record in Orlando: 2015 (72.0°F avg. temp.)
• Local population: 311,732

2. Tampa, Florida

• Average December temperature in Tampa, 1990-2020: 64.4°F
• Warmest December on record in Tampa: 2015 (73.6°F avg. temp.)
• Local population: 393,389

1. Miami, Florida

• Average December temperature in Miami, 1990-2020: 71.3°F
• Warmest December on record in Miami: 2015 (77.2°F avg. temp.)
• Local population: 446,663