As of patch 8.1.5, how old is Thrall (Go'el)?

On the 15th of may, 2019, Blizzard released their cinematic called Safe haven. This video shows Thrall and how he is living away from all the conflict that is happening on Azeroth. It also shows us something that made me want to ask this question : he is starting to get some grey hairs.

I started to dig into it on WoWpedia, then on WoWwiki, then on WoWhead until I figured that none of them seems to have the answer to this simple question.

How old is Thrall (Go'el)?

Thrall is a little younger than the Dark Portal, which is convenient since the timeline is usually described in years since the Dark Portal opened. According to the Chronicle, volume 2, he was born on Azeroth, in the year 1.

The best guess on WoWpedia is that the events of Before the Storm took place in the year 33, based on Anduin's age and that Kalec had become Aspect of Magic (which occurred at some point during the events of Cataclysm) five years before. There's nothing definitive about the passing of time in Battle for Azeroth; judging by previous timelines, the typical intent is that an expansion takes up about a year of in-game time, so it's probably still 33 during Safe Haven. Thus Thrall is about 32 years old, depending on when in the year he was born.

As for whether orcs naturally go gray in their 30s, well, that's another question. It would hardly be a surprise if his stressful time as warchief gave him premature gray hairs.