According to data provided by ShowingTime RBI based on listing activity from the area’s multiple listing service MRIS, 3,970 homes sold last month, up 2.6 percent from October 2015. It was the most sales for the month since 2009. Except for July when they dipped, homes sales have been robust throughout the year. Across the region, the number of homes sold overall this year is up 6.2 percent compared with last year.

Pending sales — those homes under contract but the deal had not closed — were also higher last month. The 4,862 sales under contract were up 1.4 percent from October 2015 and the highest level for the month since 2005.

The median price of a home sold in the region during the month of October has remained nearly constant the past three years. It was $400,000 last month, which is $1,000 more than it was in October 2015 but the same as it was in October 2014.

The jurisdiction with the most expensive median sale price last month was Falls Church, Va., at $702,500, which is up $37,500 compared to October 2015. Because of the low number of sales in that city, prices tend to be volatile.

Prince George’s County, Md., continues to be one of the more affordable places to buy a home even as its median sale price grew substantially last month to $267,137. It is $27,137 higher than October 2015, an 11.3 percent gain.

Prices were higher in the District; Fairfax city, Va., and Montgomery County, Md. The District’s median price jumped to $543,000 last month from $514,000 in October 2015. Fairfax city’s median price climbed to $525,000 from $500,000. Montgomery County’s median price rose to $403,488 from $389,000. Fairfax County’s median price nudged up to $454,000 last month from $449,000 in October 2015.

The median sale price in Alexandria and Arlington County, Va., tumbled last month. Alexandria’s median price sank to $442,000 in October, from $495,000 a year earlier. Arlington County’s median price dropped to $497,000 from $545,000.

The number of homes for sale last month fell to its lowest level in three years. The 10,393 active listings were down 18 percent from October 2015 and the third-lowest level for the month in the past 10 years. Alexandria and Fairfax and Montgomery counties had the steepest declines in inventory. Fairfax County had 22 percent fewer homes for sale last month than October 2015. Montgomery County had nearly 21 percent fewer homes for sale, while Alexandria had 18 percent fewer homes for sale.

The decline in inventory was driven mainly by the dearth of new listings. Only 5,398 homes came on the market last month, down 12.4 percent compared with October 2015. It was the third lowest number of new listings for the month in the past 10 years.