Home sale prices and transaction volumes were mainly higher last month on Hawaii island while the opposite was true on Kauai, according to trade association data for the two neighbor islands.

The most activity occurred in Hawaii island’s single-family home market, where there were 160 sales in October. That represented a 17 percent decline from 193 sales in the same month last year.

Other parts of the residential real estate market on the Big Island were higher.

The median sale price for Big Isle single-family homes was up 29 percent to $380,000 last month from $295,000 a year earlier. There were 56 condo sales on the island in October, up 33 percent from 42 sales a year earlier. And the median condo sale price was up 35 percent to $361,250 compared with $267,500 in the same period.

On Kauai the number of single-family home sales fell 25 percent to 37 last month from 49 a year ago, and the median price slipped 8 percent to $624,000 from $675,000.

Kauai condo sales decreased by 14 percent to 30 in October from 35 a year earlier. The median condo sale price was the only piece of Kauai’s housing market to post a gain, rising 40 percent to $445,000 last month from $318,000 a year earlier.

Dramatic changes in monthly sale prices are common in the two neighbor island housing markets because of what the data include and the relatively small size of the markets.

Age, quality, size and location of the homes sold can easily sway the median price, which is the point at which half the sales were at a higher price and half at a lower price, when the number of sales is small.

For example, there were three single-family home sales in the North Kohala region of Hawaii island last month for a median $325,000. A year earlier there were three sales for a median $610,000.

Sales data, which Hawaii Information Service publishes for the Kauai Board of Realtors and Hawaii Island Realtors, also include new homes sold by developers along with resales of previously owned homes.