One in every 483 U.S. households received a foreclosure notice in May, according to a report released today, which also showed that Iowa is bucking the national trend.

RealtyTrac Inc. reported that the country’s foreclosure rate last month was the highest since the real estate tracking service began its monthly reporting system in January 2005.

Foreclosure filings, which include default and auction sale notices and bank repossessions, were reported on 261,255 properties, a 7 percent increase from April and a 48 percent increase from May 2007.

Iowa ranked 41st on the list, with foreclosure actions falling 14.7 percent from April and 13.5 percent since May 2007.

RealtyTrac reported 450 foreclosures last month in the state.

With one in every 118 households receiving a foreclosure filing in May, Nevada posted the highest state foreclosure rate for the 17th consecutive month. Foreclosure filings were reported on a total of 9,009 Nevada properties, an increase of nearly 24 percent from the previous month and a 72 percent increase from May 2007.

California foreclosure activity in May increased 11 percent from the previous month and 81 percent from May 2007, helping the state continue to register the nation’s second-highest state foreclosure rate. One in every 183 California households received a foreclosure filing during the month, a rate that was 2.6 times the national average.

Arizona’s May foreclosure rate — one in every 201 households received a foreclosure filing during the month — ranked third highest among the states for the second month in a row. Arizona foreclosure activity increased nearly 12 percent from the previous month and almost 119 percent from May 2007.

Other states with foreclosure rates ranking among the top 10 were Florida, Michigan, Georgia, Colorado, Massachusetts, Ohio and New Jersey.