How Long Was the Younger Dryas?

Britannica:

between 12,900 and 11,600 years ago

Swedish wiki:

för cirka 12 800 till 11 700 år sedan

German wiki:

ca. 10.700–9.700 v. Chr.

French wiki:

de 12 850 à 11 650 ans avant le présent / soit une période de 10 900 à 9 700 av. J.-C.

English wiki:

12,900 to 11,700 years Before Present

So, begins 10 900 to 10 700 BC. Ends 9700 to 9600 BC. These years are around the beginning, around a certain middle and just after the end:

2634 BC

37.009 pmC, dated as 10,851 BC*

2621 BC

40.229 pmC, dated as 10,148 BC

2608 BC

43.443 pmC, 9500 BC

So, c. 26 years or less.

It was perhaps less cold than supposed according to this youtube:

How We Know PEOPLE Travelled FAR NORTH In The YOUNGER DRYAS
MegalithHunter | 27.V.2025
https://www.youtube.com/watch?v=yzuBu93ROvI

* The pmC back when the samples start imply 8200 extra years, since 8200 years of instant age, with some rounding. 8200 + 2634 = 10 834 BC

5730 * log(0.37009) / log(0.5) = 8217 years, without rounding. 8217 + 2634 = 10 851 BC.