Sonoma County apartment rents climbed 2 percent in the third quarter to average $1,275 a month, a real estate research company reported Thursday.

The county's rents have increased 5 percent over the past year, according to RealFacts of Novato.

During the past 12 months, the nation's average rent also climbed 5 percent, to $1,042. Rents for the same period increased 10 percent in Santa Clara County, 9 percent in San Francisco, nearly 3 percent in Napa but 1 percent in Sacramento.

Of 41 metropolitan areas around the U.S., Sonoma County had the second-highest occupancy rate, 97.1 percent, up nearly 1 percent during the past three months. Only Bakersfield had a higher rate at 97.3 percent.

RealFacts predicted the U.S. will end 2012 with its average rent 6 percent higher than a year earlier.

Landlords recognize that now is an ideal time to sell their apartments, and they will increase rents to make their properties look more attractive to buyers, RealFacts predicted.