Father is in a rehabilatation hospital after having a stroke. I have been told I am the executor of his estate. For now I don't think it is wise for him to have so much money in his checking acct. Where would be a safer place for him to store this money until needed.

Why is a checking account not safe? Its fully guaranteed under the FDIC to far more than he has. And its easily acessible when its needed. Just don't leave a checkbook or bank card at his hospital.

Totally agree with smoothy. If your father can speak and understand you and write his name, I would get a bank form putting you on the account as a co-signer. I discovered that having a POA for banking matters doesn't make it happen automatically, the bank still wants a form signed by the account holder.
You aren't executor while he is alive. You may have POA, which ceases when he dies.

I was thinking on the lines of a large amount of money sitting without earning interest. I thank you and I do have enough to think about besides his checking account right now.

Anything else is going to still earn very little but carry a far larger risk.

And at 87 he can't afford to take any losses. I'd say the same if he was 67, but not if he was 47.