CHICAGO - For The Twelve Days Of Christmas, climate change is giving to us a warmer end to December and start to January on average. The 12-day period is defined as December 25th through January 5th. Climate Central did a study of 246 locations across the country to see how temperatures have been changing during this stretch since the winter of 1969-1970. It should come as no surprise that the period has been warming over the past 51 years. 97% of the locations they analyzed have seen an increase in the average temperature for this 12-day period since 1969.
For 94% of locations the warming has been greater than 1°. It has exceeded 3° for 75% of locations, and 5° for 37% of locations. Chicago has seen a bump of 5.6° for the Twelve Days Of Christmas period. That means the last six days of December through the first five days of January have jumped nearly 6° here in just over 50 years.
Our neighbors to the north have seen an even bigger jump in temperatures. Milwaukee has warmed nearly 9° for the period.
You can still dream of a white Christmas but warmer winters are having an impact. Idaho, Minnesota, Maine, Upstate New York, and the Allegheny, Rocky, or Sierra Nevada Mountains have the best chance of seeing a white Christmas but Climate Central's studies have shown the dream is dwindling for most of the country. Here are some of their conclusions:
- The historical probability of a white Christmas (at least 1 inch of snow accumulation on December 25) is slimmer for the rest of the contiguous U.S. based on NOAA’s analysis of the most recent climate normals (1991-2020).
- Winter has been the fastest-warming season for most of the U.S. since 1970, increasing the likelihood of winter precipitation falling as rain rather than snow.
- Warmer winters are disrupting the water cycle in the western U.S., which relies on mountain snowpack for much of its freshwater supply. Decades of shrinking snowpack has reduced snow-derived freshwater in the west by 15-30% since 1955.
Climate Central also notes impacts from warmer winters beyond just fewer white Christmases:
- Christmas trees feeling the heat: Wildfires and a record-breaking heatwave in June 2021 scorched Christmas tree farms in the Pacific Northwest. This potentially impacts tree supplies and prices this year and into the future as heat-stunted seedlings mature.
- Winter recreation meltdown: Activities like skiing, skating, ice fishing, and snowman-building are threatened by a rising number of above-freezing days.
- Festive food and drink: Maple syrup, cocoa for hot chocolate, apples for pie and cider, and brandy for eggnog are all climate-sensitive. Warmer, shorter winters can disrupt growth and production timelines, or shift them poleward altogether.
- Life in the North Pole: Waning sea ice coverage, changing temperature and precipitation trends, and shifting vegetation are transforming Arctic ecosystems including icons of the holiday season such as polar bears and reindeer.
It's not just the Twelve Days Of Christmas period that is getting warmer. The United States had its third warmest autumn in history this year and November was the earth's fourth-warmest since record-keeping started in 1880. That warmth has spilled over into December. Our country has seen nearly 5000 record high temperatures so far this month compared to only 149 record low temperatures. With greater than a 99% chance 2021 is virtually a lock to end up among the top ten warmest years on record for our planet.