It would take nine months to sell all the homes listed for sale in Newport Beach at the current sales pace, according to Steven Thomas at Altera Real Estate.

That made Newport Beach Orange County’s coldest housing market in late November. Portola Hills, on the other hand, was the county’s hottest, with all the listings there disappearing — in theory — in 45 days.

Thomas calculates the “market time” for each community by comparing how long it theoretically would take to sell all the homes on the market at the current sales pace.

Thomas reported:

• The “hardest” O.C. town to find a home to buy in terms of “market time” (supply of homes for sale vs. new purchase deals inked in past month) is  Portola Hills at 1.5 months (45 days) to theoretically sell all for-sale homes at the current buying pace. A year ago, this town was at 1.4 months (42 days).
• The market time of the five “hardest to buy” communities combined was 2.4 months as of last week. These five communities with the shortest market times had 10% of the county’s supply of homes for sale, but 17% of homes in escrow.
• “Hardest” market to sell a home in, based on the same math, was Newport Beach with a market time at 9.1 months to theoretically sell all for-sale homes at the current buying pace. A year ago, this town was at 8.4 months.
• The five “hardest to sell” markets have a combined market time of 8.3 months and were 10% of the supply of homes for sale and 5% of homes in escrow.
• All told, countywide market time was 4.0 months last week.
• All told, 5% of the communities tracked by Thomas had “market times” less than 2 months, a clear sellers’ market. Four weeks ago? None. It was 45% a year ago.
• More stats from Altera Real Estate HERE!

Chart looks at the five hottest and five coldest markets in O.C. as of last Thursday (supply for sale; new deals made; market time in months vs. a year ago and average listing price) by Thomas’ market time math.