He carried out his final sentencing yesterday, jailing trout poacher Thomas Tawha for 12 months.
Sentencing was the hardest part of being a court judge, and often the most memorable, he said.
"I think if you speak to any court judge they will say sentencing is the most difficult aspect of the job because you are depriving people of their liberty, it can be hard to not take that home with you at night.
"At the end of the day you need to do a brain dump but even then, it's the humanity or lack thereof that sticks with you."
Judge Weir said his new role, still based in Rotorua, would be a "different sort of action from court action".
"It is a multi-faceted role that will be dealing with the root of many crimes - alcohol and people getting into trouble when they're highly intoxicated.
"If I have noticed anything in the last 15 years it's that there is more violence now than when I started in 2000 and an enormous amount of that has to do with alcohol," he said.
"For years it has been said that being a court judge is like being an ambulance at the bottom of the cliff. With this new appointment, hopefully I will become the ambulance at the top of the cliff."
He said his new role as chairman would introduce interesting challenges.
"It will be a bit of a change but after the five year term is up you never know, I might find myself back at district court."
