Trees were quite advanced in mid-April 1821. According to observer at College Hill, Ohio (just northwest of Cincinnati), Pawpaws had leaves, Black Walnuts had shoots with young leaves & oaks had young leaves. Tuliptrees had leaves.
Then a devastating 2007-type Arctic outbreak hit (but it hit later than the 2007 outbreak). All leaves reportedly turned black on the forest trees, shriveled up & fell. This was reported from College Hill, Cincinnati, Ohio, as well as Vincennes, Indiana & even Nashville, Tennessee. Crops were completely wiped deep into the southern U.S. & the one Cincinnati area observer reported zero fruit that year.
The College Hill, Ohio observations show a morning low of 20 on April 18. Log shows only 32 degrees at noon. A high temperature of 40 was reported in the city of Cincinnati that day.
Snowfall was reported as far south as Crawfordsville, Indiana, or 35 miles northwest of Indianapolis & heavy snowfall near Newark, New Jersey led to “good sleigh riding for one week”.
This followed the extreme drought of 1820 over our region with intense heat.
A temperature anomaly reconstruction (with as many thermometers, observation sites & diaries to newspapers as possible used) shows that mid-April 1821 cold was similar to early April 2007 cold Plains to Northeast, while warmth likely dominated area west of the Continental Divide.
Comparing tree ring Palmer Drought Index data (courtesy of Columbia University) in Summer 1821 to Summer 2007.
There are superficial similarities with intense drought over a large area in our region in 1821. This drought was just a bit more south in 2007 (it was bad here in 2007 though).
The wetness in the Plains of 2007 is seen in the 1821 tree ring data as a wetness anomaly from Texas & then into the High Plains/Rockies.
Keep in mind that there is a lot of interpolation between points in the 1821 data, while the 2007 is much more dense with PDSI’s given per each climate division.