I've been playing mine in all sorts of climates for some seven years, and do quite nicely- For the first year, I just misted it every so often when it got too tight. Since then, once a year, I rub it with either a leather conditioner or just plain old hand lotion. (Not much- enough to make the skin supple.) At that point, I have to let it sit a day or two before it tightens up enough again to play. But other than the once a year treatment, it gets tuned with guinness- and fire. ~gryn~ No kidding. Guinness when it's too tight, fire when it's too loose. It seems to love it.
I should include one side note- I went out of my way to find a ~calf~ skin bodhran, which is less common, and the skin is richer and more supple in general that my previous goatskin drum, and might respond a bit differently than goat.