U.S. fixed mortgage rates this week climbed above 4 percent for the first time in almost five months as the U.S. 10-year treasury notes yield remained floating well above 2 percent in the past several weeks amid improving economic data, said the Primary Mortgage Market Survey released Thursday by Freddie Mac.

The mortgage giant said that 30-year fixed-rate mortgage (FRM) was 4.08 percent for the week ending March 22, breaking the 4 percent barrier that had held since October 27, 2011. The 15-year FRM averaged 3.30 percent, up from its previous week average of 3. 16 percent.

The five-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) averaged 2.96 percent, up from last week when it averaged 2. 83 percent, and the one-year Treasury-indexed ARM averaged 2.84 percent this week, up from last week's 2.79 percent.

The average rates don't include extra fees, known as points, which added the rates up by 0.6 percent to 0.8 percent.

"Mortgage rates are catching up with increases in U.S. Treasury bond yields due to an improving assessment of the state of the economy by the Federal Reserve," said Frank Nothaft, vice president and chief economist, Freddie Mac.

To calculate average mortgage rates, Freddie Mac collects rates from lenders across the country on Monday through Wednesday of each week.

Freddie Mac was established by Congress in 1970 to provide liquidity, stability and affordability to the nation's residential mortgage markets.