December 2021: The Second-Warmest Holiday Season in Phila.’s 147 Years of Weather Records

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melted snowman in a yard
Image via MBK (Marjie) at Creative Commons.
Rising December temperatures are precipitating rising environmental concerns.

If December 2021 felt like Santa needed Bermuda shorts and Frosty could have used an iced tea, there’s a reason: It was the second-warmest final month of a Philadelphia year in 147 years of record keeping. Frank Kummer simmered the particulars for The Philadelphia Inquirer.

December 31 registered an average daily temperature of 51 degrees, bringing the monthly average to 45.3 degrees. This put the average temperature in Philadelphia at 6.7 degrees above normal. Meanwhile, the weather was also dry with just 1.64 inches of precipitation, or 41 percent of normal.

“It certainly was an unusually warm month,” said Dave Dombek, a senior meteorologist with AccuWeather. “We had a handful of cold days, but if you look at the low temperatures, a lot of those days didn’t even go below freezing at night.”

Currently, six out of ten warmest Decembers have already occurred in this century.

The increase in temperatures fits in with a long-term trend under climate change, according to Climate Central, a nonprofit composed of scientists and journalists. The group determined that Philadelphia Decembers are getting milder, with an overall increase of 4.4 degrees in the average temperature since 1970.

The only December that felt more tropical than the one just past was 2015’s.

December 2021 also has the second-fastest rate of warming in the region, with January being the first.

Read more about rising temperatures in The Philadelphia Inquirer.

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