While Maine home sales increased in May compared with a year earlier, median prices continued a three-month decline from 2013 prices, the Maine Association of Realtors said Monday.

Detached, single-family home sales totaled 1,302 in May, up from 1,214 in May 2013, an increase of 7.25 percent, the association said.

The increased sales follow a recent trend. In April, home sales were up 8.3 percent from a year earlier, and in March, year-over-year sales were up 12.6 percent.

However, the median sale price decreased 4.8 percent in May, the association said. The median sale price indicates half the homes sold above that price and half sold below.

It was $169,950 in May, down from $178,500 in May 2013.

April results were similar, with the median price down 3.4 percent, and in March it was down 4.7 percent, according to the association.

“With summer finally here, and tourists entering the buying market, we are seeing (sales) volume increases,” said association President Angelia Levesque. “High inventory levels in some areas of the state are keeping prices down, and the market is adjusting. When you combine that information with low interest rates, it indicates a great time to buy.”

Nationally, home sales followed the opposite trend, with sales volume down and median price up compared with May 2013.

The National Association of Realtors said Monday that single-family home sales in the United States decreased 5.7 percent from a year earlier, while the median price increased 4.9 percent to $213,400.

In the Northeast, both the number of sales and the median price were down in May, by 3.1 percent and 0.9 percent, respectively, the national association said.

Levesque, of Better Homes and Gardens / The Masiello Group in Bangor, said inventory is up in her area partly because of foreclosure homes coming on the market, which often are purchased by investors for cash.

First-time buyers also have been more active in the market, she said. Both investors and first-time buyers tend to purchase lower-priced homes, which drives down the median price.

Another factor that kept Maine’s median price down in recent months was the weather, Levesque said.

Because spring was so cold, a lower-than-average number of vacation-home buyers entered the market, she said. Those buyers tend to purchase higher-priced homes.

Now that the weather is warm, Levesque said she expects strong sales will continue throughout the summer. As for what will happen with prices, she said it is difficult to tell.

“I wish I had a crystal ball, and I don’t,” she said.

Cumberland County also has seen a boost in housing inventory, which tends to drive down prices, according to Michael Sosnowski, owner of Maine Home Connection in Portland.

“In May, inventory in Cumberland County was at its highest level since May 2010,” he said. “Obviously buyers have a lot of choice in terms of what property they want.”

Homes at all price levels, from starter homes to seaside mansions, were selling for less than they were a year earlier, Sosnowski said.

Still, he said homes in good condition that are priced correctly continue to sell quickly.

In addition to statewide figures, the Maine Realtors Association also tracks home sales and prices by county on a rolling, three-month basis.

In Cumberland County, both sales volume and median price were down for the three months ending May 31 compared with the same period a year earlier.

There were 788 single-family homes sold during the most recent three-month period, down 5.2 percent from 831 homes during the same period of 2013.

The median price was $235,000, down 4.5 percent from $246,000 a year earlier, according to the association.

Waldo County had the biggest boost in sales volume. Home sales for the three-month period were up 50.8 percent compared with a year earlier.

Piscataquis County had the greatest increase in median price. For the three months ending May 31, it increased 17.4 percent from the same period of 2013, from $90,000 to $105,700, the association said.