The relatively small neighbor island housing markets of Kauai and Hawaii island produced some pretty big jumps last month for median home sale prices, which surged by close to $100,000 or more.

Hawaii Information Service released a report Tuesday on behalf of the Kauai Board of Realtors and Hawaii Island Realtors that showed prices for new and previously owned homes sold in June were mostly higher while sale volume was more mixed.

One of the big swings occurred in the median sale price for single-family homes on Kauai, which surged 21 percent to $690,999 in June from $570,000 in the same month last year.

Part of the reason appeared to be more sales of million-dollar homes in the Koloa region, which includes the Poipu resort area. There were 10 sales in Koloa for a median $1 million last month, compared with eight sales for a median $577,500 a year earlier.

The median is a point at which half the sales were for more and half for less. This measure — influenced by the size, quality, age and location of homes — is susceptible to significant swings, especially when the pool of sales being counted is small. Also, sales reported by Hawaii Information Service include new homes that typically carry higher prices than older homes of comparable size.

There were 63 single-family home sales on Kauai last month. That was up 34 percent from 47 sales a year earlier.

Another big price swing happened in the Big Island’s single-family home market, where the median price jumped 30 percent to $371,500 last month from $285,000 a year earlier.

A major factor in this gain was more sales at the high end of the market in North Kona where there were 50 sales for a median $587,500 last month compared with 34 sales for a median $560,000 a year earlier.

The low end of the Big Island’s housing market was anchored in the Puna district, where there were 66 sales for a median $209,650 last month compared with 68 sales for a median $141,375 a year earlier.

Overall, there were 185 single-family home sales on the Big Island last month, up 9 percent from 170 a year earlier.

In the Big Island’s condominium market, the median sale price decreased 14 percent to $246,000 in June from $285,000 a year earlier. That was based on 49 sales, down 11 percent from 55 sales in the same comparable period.

Kauai condos sold for a median $344,000 last month, up 12 percent gain from $306,504 a year earlier. The number of sales plummeted 48 percent to 22 from 42 in the same period.