U.S. mortgage application activity climbed to their loftiest level in over four months despite 30-year home borrowing costs rising to their highest levels since March, the Mortgage Bankers Association said on Wednesday.

The Washington-based group said its index on mortgage requests rose for a third straight week. It was up 4.5 percent from the prior week to 424.4 in the week ended Jan. 19, which was the highest since 462.1 in the Sept. 8 week.

Average interest rates on 30-year conforming mortgages, or loans whose balances are $453,100 or less, rose to 4.36 percent, up 3 basis points from the prior week. This was highest since 4.46 percent in week of March 17.

The average contract interest rate for 15-year fixed-rate mortgages increased to its highest level since September 2013, 3.81 percent, from 3.77 percent.