National housing prices increased 2.6% in April 2010 compared to April 2009 in the CoreLogic (CLGX) monthly home price index (HPI). It's the second month in a row that prices have increased from the same month one year ago. The April increase comes after a 2.3% year-over-year increase in March. The HPI was upwardly revised from an original projection of a 1.7% increase for March. Month-over-month, the national average HPI increased 0.8% in April compared to March, up from the 0.1% increase from February to March. The chart below shows year-over-year prices changes by state: Since the HPI peaked in April 2006 to the current HPI level, prices are down 29.5%. In April 2009, all of the 100 core based statistical areas (CBSAs) CoreLogic tracks experienced a year-over-year decrease. Since then, the number of CBSAs with positive year-over-year gains has increased every month. In April 2010, 60 of 100 markets experienced increases. “The monthly increase in the HPI shows the lingering effects of the homebuyer tax credit,” said Mark Fleming, chief economist for CoreLogic. “We expect that we will see home prices remain strong through early summer, but in the second half of the year we expect price growth to soften and possibly decline moderately.” Hawaii lead all states in year-over-year price appreciation at 13.4%, followed by Massachusetts (7.4%), California (7.3%), Virginia (6.5%) and New Hampshire (5.2%). Idaho leads all states in year-over-year price decline in April, with the HPI down 7.2%, followed by Illinois (5.8%), Nevada (4.6%), Maryland (4.3%) and Washington (3.7%). When distressed sales are removed from the equation, CoreLogic said prices increased 2.2% year-over-year in April, better than the 1% increase in the non-distressed HPI during March. From peak to current, excluding distressed properties, the change in the HPI is -21.1%. Excluding distressed sales, Hawaii again leads all states in year-over-year price increases at 10.6%, followed by California (8.4%), North Dakota (6%), New York (3.7%), and Virginia (3.6%). The states with the worst HPI levels excluding distressed sales were Nevada (5.6%) Michigan (4.1%), Arizona (3.4%), Florida (3.4%) and Washington (3.1%). Write to Austin Kilgore. The author held no relevant investments.