We are expecting a foot of snow the next couple of days in Philadelphia, but on this date in 1921, about half of the US was over 80 degrees.
The heat then moved east and brought record warmth to the East Coast.
21 Mar 1921, 2 – The Courier at Newspapers.com
The warmth remained most of the year, and 1921 was the second warmest year on record in the US, after 1934.
1921 was the only year where more than two thirds of days were above 60F in the United States.
1921 had the second highest percent of days over 70F.
1921 had the fourth highest percentage of days above 80F
The frequency of 90 degree days in 1921 was well above average, but less spectacular.
The frequency of below 20F nights was fifth lowest on record in 1921.
The interesting thing about 1921, is that it wasn’t extremely hot like 1931, 1933, 1934, 1936 or 1954 – but the weather was very warm throughout the year. CO2 was barely above 300 PPM at the time.