A steady growth trend continued over 2012 numbers as Maine home sales increased 20 percent in August.

Maine real-estate firms sold 1,506 single-family, existing homes in August, an increase from the 1,255 in August 2012, according to the Maine Association of Realtors.

In addition, the median sales price for homes sold was $182,000, a 7-percent increase from the median sales price posted in August 2012, the association reported Thursday.

“There’s a continued optimism in the market,” Bart Stevens, president of the Maine Association of Realtors, said in a statement.

The association provides data by county in rolling quarters, the most recent being June through August. During that period, all counties saw an increase in home sales between this three-month period and the same one last year — except Hancock, which saw one less house sold during the three-month period (158 compared to 157), and Washington County, which saw no change (73 homes sold in both periods).

Franklin County was the steepest increase during the three-month period with 88 homes sold, a 54.4-percent increase from the 57 sold during the same period last year.

Median sales prices, however, were more volatile. Piscataquis and Washington counties saw the median sales price for homes sold during the three-month period fall by 23.7 percent to $67,500 and 22.7 percent to $85,000, respectively.

The county with the largest increase in median sales price was Lincoln County, which saw its median sales price increase to $219,500, or 25.4 percent.

Nationally, sales of single-family, existing homes increased 12.8 percent in August, and the national median sales price of $212,200 represents a 14.4 percent increase, according to the National Association of Realtors. Regionally, sales in the Northeast rose 12.7 percent and the regional median sales price increased 7.6 percent to $268,800.