May was an extraordinary month for housing markets on Kauai and Hawaii island, with industry trade associations reporting several gains of at least 40 percent in sales volume and median prices.

The biggest increase was in how many single-family houses were sold on Kauai. There were 52 sales in May, up 49 percent from 35 sales in the same month last year, according to data from the Kauai Board of Realtors released Monday by Hawaii Information Service.

The median price for single-family houses on Kauai soared almost as much: 48 percent to $752,500 last month from $510,000 a year earlier.

Much of this median sale price gain was concentrated in the Kawaihau region, where there were 16 sales last month for a median $705,000 compared with a year earlier when there were 10 sales for a median $542,500. Other parts of the island also had dramatic increases in the median price, which can be affected by the size, age, quality and location of homes that are sold because the measure is a point at which half the sales are for a higher price and half for a lower price.

In Kauai’s condominium market, the number of sales bumped up only slightly to 40 last month from 37 a year earlier. But the median price jumped 40 percent to $475,000 from $340,000 and was largely driven by sales in the Hanalei area, where there were 10 sales last month for a median $581,000 compared with seven sales for a median $399,000 a year earlier.

On Hawaii island there was a big gain in the number of condo sales while other parts of the market had more modest increases along with one big drop.

Data from Hawaii Island Realtors provided by Hawaii Information Service said there were 93 condo sales last month on the Big Island, up 41 percent from 66 sales a year earlier. The median price, however, sank 20 percent to $273,000 from $339,500 in the same period.

Hawaii island’s median condo price was pulled down by a surge in sales at the lower end of the market in South Hilo, where 26 condos sold for a median $109,606 last month compared with seven sales for a median $199,000 a year earlier. At the high end of Hawaii island’s condo market, in South Kohala, there were 24 sales for a median $677,000 last month compared with 22 sales for a median $500,000 a year earlier. Prices in North Kona were closer to flat on 42 sales for a median $312,500 last month compared with 36 sales for a median $301,750 a year earlier.

In Hawaii island’s single-family home market, there were 238 sales in May, up 9 percent from 218 sales a year earlier. The median price was up just 3 percent to $322,000 from $314,000.