Two neighbor island housing markets suffered major sales slowdowns in October while median prices moved up and down, according to industry data released Monday.

Sales of single-family homes and condominiums on Hawaii island and Kauai dropped as much as 41 percent, according to a report from Hawaii Information Service based on data from the Hawaii Island Realtors and Kauai Board of Realtors trade associations.

The biggest drop was in Kauai’s condo market where there were 34 sales last month, down 41 percent from 58 sales in the same month a year earlier.

Single-family home sales on Kauai dropped 33 percent to 34 in October from 51 a year earlier.

Major decreases also happened on the Big Island. Single-family home sales there fell 22 percent to 181 last month from 231 a year earlier, and condo sales slid 11 percent to 67 from 75 in the same period.

Median prices also had some double-digit swings, but were split with increases and decreases.

Kauai single-family houses sold for a median $745,000 last month, up 6 percent from $700,000 a year earlier. Condos on Kauai sold for a median $402,500 last month, down 13 percent from $465,000 in the same comparable period.

On Hawaii island the median price for single-family homes sold last month fell 13 percent to $335,000 from $383,250 a year earlier. For condos the median sale price was the same as single-family homes — $335,000 — but reflected a 26 percent gain from $265,000 a year earlier.

The median price is a point at which half the sales were for a higher price and half for a lower price. This measure can be affected by the age, size, quality and location of homes sold.

It’s not unusual for neighbor island housing markets to have dramatic swings in sales or median prices compared with Oahu, in part because the volume of sales is smaller and because the trade associations for real estate agents on Kauai and Hawaii island count sales of new homes in addition to previously owned homes. On Oahu, only previously owned homes are counted. By counting new projects, sales can spike when a new subdivision or condo is completed and developers close sales in bulk. New projects also tend to carry higher prices than most existing inventory.