According to a third-quarter report Wednesday from RealFacts of Novato, Bay Area apartment rents have jumped 11.4 percent from last year to an average of $2,234 a month.That's the highest it's been in records going back two decades, a company spokesman said.ents in that city average $2,498 a month, a 17.6 percent increase from last year. Her plan: move to Georgia in a few weeks and find a more affordable place in Atlanta.Here's a breakdown of average apartment rents by county: Santa Clara County: $2,369 a month, up 10.7 percent.