Research Report by Climate Central
Hearing about climate change may bring heat waves and sweltering summers to mind, but in most regions in the U.S., winter temperatures are also on the rise. In spite of last year’s East Coast blizzard and polar vortex, winters have, on average, been getting warmer since the 1970s. One of the starkest examples of this is the overall drop in the number of nights below freezing in most cities.
For many Americans the idea of fewer freezing nights is a welcome prospect. But warmer winters can have negative impacts: ski resorts need freezing temperatures for snow, some crops rely on a chill period, and pests can flourish year-round if winter temperatures aren’t cold-enough for them to die off.
Climate models project that freezing temperatures will become even less frequent as greenhouse gas emissions further increase global temperatures. What will these warming winters feel like? For our Winter Loses Its Cool interactive we have projected the number of nights below freezing for the end of this century for 697 cities, and then showed which U.S. city currently experiences that number of freezing nights. Several striking examples are highlighted above, but explore the interactive to find out how the cold season will be affected in your city.
By the end of the century, assuming current CO2 emissions trends continue until the end of the century, Helena, Mont., will see about 85 fewer freezing nights, which is comparable to Lubbock, Texas, today. Buffalo, N.Y., which currently experience about 124 freezing nights each year, will only see about 57 a year in 2100, making it more like Charlotte, N.C. Ann Arbor, Mich., will see less than half its current number of nights below freezing (131), which is more like Huntsville, Ala. (60).
In fact, more than 80 percent of the cities we analyzed—593 of the 697—could see at least a 50 percent reduction in number of nights below freezing, and more than 20 percent—145 of the 697—could see at least a 75 percent reduction. There are even 28 cities, mostly those that currently experience between 10 and 20 nights below freezing, that may see at least a 90 percent reduction. For these cities, freezing nights will become a rare event that occurs about once a year, comparable to the current conditions in Brownsville at the southern tip of Texas.
This analysis only accounts for daily minimum temperatures, which typically occur at night, and doesn’t incorporate windchill, which contributes to how winters feel. This projected warming also assumes greenhouse gas emissions keep increasing through 2080 as they have been for the past few decades.
Click here to see a similar analysis of how summers may feel by the end of the century.
This article is reproduced with permission from Climate Central. The article was first published on February 4, 2015.