Housing markets on Hawaii island and Kauai got off to a sluggish start in 2011, with sales and prices mostly flat or down in January.

The declines occurred mainly on Hawaii island, while there was little change on Kauai, according to statistics released Monday by data collection firm Hawaii Information Service.

Single-family home sales on Hawaii island were down about 10 percent to 95 in January from 105 in the same month last year. The median price, which is a point at which half the sales were for more and half for less, was down 4 percent to $231,000 from $240,000.

Homes in Puna accounted for most of the decrease in sales, with 29 homes sold last month compared with 35 a year earlier. The next busiest region for sales was North Kona where 26 homes sold last month compared with 21 a year earlier. Median prices in both regions were up, as they also were in Hamakua, North Kohala and South Kona. But lower median prices in North Hilo, South Hilo, South Kohala and Kau dragged the island-wide median down slightly.

Condominium sales on Hawaii island fell 19 percent last month to 35 from 43 a year earlier. The condo median was the only bright spot in the market. It posted an 11 percent gain to $200,000 from $180,000.

Nearly all the condo sales on Hawaii island occurred in two areas — South Kohala, where the median surged 46 percent to $489,000 on 13 sales, and North Kona, where the median dropped 30 percent to $135,500 on 19 sales.

On Kauai, the number of single-family homes and condos barely moved. There were 30 single-family home sales last month, up from 29 a year earlier. There were 21 condo sales compared with 20 in the same year-over-year period.

Kauai’s median single-family home price was down 4 percent at $402,500 last month from $421,000 a year earlier. The condo median was unchanged at $270,000.