In 1989, NOAA said most global warming occurred before 1919 and declined from 1921 to 1979.
“Analysis of the warming since 1881 shows most of the increase in global temperature happened before 1919 — before the more recent sharp rise in the amount of carbon dioxide in the atmosphere, said Thomas Karl, of the National Oceanic and Atmospheric Administration’s National Climatic Data Center in Asheville, N.C.
While global climate warmed overall since 1881, it actually cooled from 1921 to 1979, Karl said.”

Dec 07, 1989, page 44 – The Tyler Courier-Times at Newspapers.com
Since then they have reversed both of those trends and erased the record heat of 1921.

Global Temperature | Vital Signs – Climate Change: Vital Signs of the Planet


04 Sep 1921, 61 – New York Herald at Newspapers.com


16 Oct 1921, 104 – The San Francisco Examiner at Newspapers.com



TimesMachine: October 3, 1921 – NYTimes.com

#448 – The Graphic : an illustrated weekly newspaper. … v.104 (Jul.-Dec.1921). – Full View | HathiTrust Digital Library
“Monthly Weather Review – November, 1922 (Page 589)
The Arctic seems to be warming up. Reports from fishermen, seal hunters, and explorers who sail the seas about Spitzbergen and the eastern Arctic, all point to a radical change in climatic conditions, and hitherto unheard-of high temperatures in that part of the earth’s surface.
In connection with Dr. Hoel’s report, it is of interest to note the unusually warm summer in Arctic Norway and the observations of Capt. Martin Ingebrigtsen, who has sailed the eastern Arctic for 54 years past. He says that he first noted warmer conditions in 1918, that since that time it has steadily gotten warmer, and that to-day the Arctic of that region is not recognizable as the same region of 1868 to 1917.
Many old landmarks are so changed as to be unrecognizable.
Where formerly great masses of ice were found, there are now often moraines, accumulations of earth and stones. At many points where glaciers formerly extended far into the sea they have entirely disappeared.
There were few seal in Spitzbergen waters this year, the catch being far under the average. This, however, did not surprise the captain. He pointed out that formerly the waters about Spitzbergen held an even summer temperature of about 3° Celsius; this year recorded temperatures up to 15°, and last winter the ocean did not freeze over even on the north coast of Spitzbergen.”

THE CHANGING ARCTIC in: Monthly Weather Review Volume 50 Issue 11 (1922)