January 21 afternoon temperatures have dropped several degrees in the US since the 19th century, as has the likelihood of warm weather on this date.
On January 21, 1906, almost half of USHCN stations were over 60 degrees, and one out five were over 70 degrees.
There were 70 degree temperatures in many locations in New York, and 60 degree temperatures in New Hampshire.
Temperatures on this date in 1906 were 50-60 degrees warmer than this year.
US Weather – Current Temperatures Map | WeatherCentral.com
Temperatures were also very warm on this date in 1909, with the average maximum being 54 degrees.
Carbon dioxide seems to be having difficulty trapping heat as its concentration increases.
via The Deplorable Climate Science Blog
January 21, 2019 at 09:31AM
Iowa Climate Science Education 