The average rate on a 30-year loan has jumped from about 5 percent to more than 5.3 percent in just the past week. As mortgages get more expensive, more would-be homeowners are priced out of the market—a threat to the fragile recovery in the housing market.

And if you wanted to refinance at a super-low rate, you may have missed your chance. Mortgages under 4 percent are still available, but only for loans that reset in five or seven years, probably to higher rates.