I have just made my first batches of mmf and they seem very successful (so far!).
I want to use it in several days time and am unsure if I should store it at room temperature or in the 'frig.
I live in Australia and our humidity is very, very high at present.
Room temperature currently is varying from 13 degrees Celsius to 30 degrees Celsius.
I think this is a range from 55 to 83 degrees Farenheight, in Australian conversion but I may be wrong.
It can change this much across a 24 hour period.
How should I store my mmf for about 5 days?
I have double wrapped it in good quality cling plastic wrap.
I would really appreciate any help.

Hiya, I store mine tightly wrapped in gladwrap and then in ice-cream containers in the fridge, if you get it out a an hour or two b4 you want to use it to allow it to come back to room temp so its easier to use, or you can put it in the microwave for like 5 second increments until it softens alittle. I'm in New Zealand and it seems to work for our temperatures. Hope this helps and good luck with your cake.

I keep mine in the pantry for 3-4 months max wrapped in freezer ziplock bags. I use Rhonda's ultimate MMF. I can taste when it's too old..Generally, MMF doesn't need to be kept in the fridge. However, .I live in western Canada in a province that is fairly dry.

I coat with Crisco, wrap in plastic, seal into a Ziploc bag, and store in the pantry inside an ice cream container. Uncolored it keeps for 2-3 months even in summer humidity here in Quebec. Colored it starts to be hard to handle after six weeks or so, the darker the color the faster the breakdown. At that point I usually set it aside for mixing with gumpaste for modeling.

I've tried keeping it in the fridge, but I don't like the time it takes to come to room temp and, really, there's no reason to do so. I wouldn't store an open bag of marshmallows in the fridge, nor would I store my ps or Crisco in the fridge, and I see no reason to store a mix of those products in the fridge either.