The Years of Dryness refer to a period of crop failures in the region of Bahar spanning from 1413 to 1418.
Whilst they are not always seen as part of the Decades of Devastation the years of dryness, leading to recurring crop failures, did their part in weakening the region for the calamities which came next. (Like wars, human rebellions and goblin invasions).
At the height of the Years of Dryness Irrigation canals remained empty, grain stalks withered from the heath and whole herds of livestock were decimated due to lack of fodder. The first years led to farmers heavily indebting themselves to keep up their standards of living, when the rains didn't return quickly enough after that many were forced to default on their debts and ended up sold into slavery so that their creditors could at least recover something (greatly decreasing the amount of armed free men who would lose the most in case of successful invasions or rebellions). Hungry peasant grew to resent their elvish overlords for taking the best land for themselves. High food prices led to bread riots breaking out in cities forcing the kings to empty their coffers by importing grain from abroad. In neglected regions whole towns were abandoned by their inhabitants who went looking for work at farms or in crime to feed themselves.
It is generally seen as causing a lot of the resentment which later led to the human rebellions, not only because they decreased trust in the elvish establishment. But also because sun elves tended to be favored in government aid. Though the worst part of it was that it created an underclass of former free farmers and artisans who lost everything and would later make both a fertile breeding ground of human rebels and also collaborators and foot soldiers for the invading goblins.