Purchasing a Refurbished Imac

The optimum time to buy an Apple refurbished iMac is when you need or want one and a model that fits your needs is available.

Per the terms of use that we all agree to we cannot speculate and your question is asking for pure speculation.

There are two periods in the trading year when more business is done and that may mean more items could become available. I am thinking of after Christmas and after the 'Black Friday' discount day. As RK says, we cannot speculate but these periods can reasonably be expected to boost availability ... always allowing time for the refurbishment to be done.