In short, it's unlikely that mortgage interest rates will fall much further in September, even if that doesn't mean that you should stop monitoring the market to take advantage of minor drops.

Today’s interest rate for a 15-year fixed-rate mortgage is 5.125%, which is unchanged from yesterday. The monthly payment for a $250,000 mortgage with a 15-year term and a fixed interest rate of 5.5% would be $2,042.71. The payment for the same loan with a 6% interest rate would be $2,109.64.

If you have a mortgage rate of 6.9% or higher, have a good credit score, and at least 20% equity in your home, it could pay to refinance.