Beating summer expectations, August home prices ticked up 5 percent across 19 major U.S. markets in what real estate broker Redfin called an “indicator of a housing market getting stronger.”

According to the broker, home sales went up 1.4 percent year-over-year, eclipsing a 2.5 percent decline in July. Home sales increased from 26.7 percent to 27.6 percent last month.

Of major U.S. cities, prices in Phoenix went up by 31 percent year-over-year. Home prices meanwhile fell 4 percent from August last year.

Homes sold fastest in six markets, including San Jose (52.3 percent), San Francisco (45.6 percent), Ventura (43.5 percent), Inland Empire (42.8 percent), San Diego (41.2 percent), and Los Angeles (39.8 percent). Properties sold less well in Boston (3.9 percent).

When it came to inventory, Redfin found year-over-year tailspins in seven markets, with most of them in California. Those included Sacramento at a loss of 65.7 percent; Ventura, at 62.6 percent; Inland Empire, 57.9 percent; San Francisco, 56.2 percent; San Jose, 55.8 percent; San Diego, 52.4 percent; and Los Angeles, 52.3 percent.

“In our business, Redfin saw a monster surge in August closings,” Redfin CEO Glenn Kelman said in a statement. “While September now seems likely to be down nearly 20% from August’s peak, we were surprised after Labor Day to see a relatively large number of new customers begin touring homes for the first time, which has given us reason to be optimistic about the rest of the fall and even the year ahead.

“The main reason there aren’t more sales is that there aren’t more sellers, as most would-be sellers are holding out for more price gains in 2013 before listing their home, and many of today’s move-up buyers just plan to rent out their old place,” he added.