It depends on whether the credit unions & banks follow the Fed with interest-rate reductions of their own. Sometimes they follow lockstep, other times they wait to see what their competitors do, other times they offer sales that have nothing to do with the Fed's actions, and sometimes they don't change.
PenFed lets you set a mortgage watch on their rates, and you get an e-mail when they meet your criteria. BankRate.com also keeps an eye on mortgage data...
The book written on E-R.org, "The Military Guide to Financial Independence and Retirement", on sale now! For more info see "About Me" in my profile.
I don't spend much time here anymore, so please send me a PM. Thanks.