Homes sold in April are also priced 6 percent higher than those in January. According to the most recent pricing data, that could mean an additional $17,000 for sellers listing the typical home prices around $306,000. One caveat is that realtor.com is looking at average prices and does not take into account the type of homes for sale at different times of year. Larger, more expensive homes tend to be listed in the spring because families like to move over the summer, during school vacations.

Homes listed in the first week of April get 14 percent more online views on average and are likely to sell six days faster than the average during the rest of the year.

Timing is everything, especially in a housing market that has been less than dependable lately. So if you want to get the best price for your home in the shortest amount of time, you'd better list it next week, at least according to realtor.com.

"Given the time it takes from listing to close, putting a home on the market in early April positions sellers to attract buyers seeking to close and move before the beginning of school year," said Danielle Hale, chief economist for realtor.com.

The number of buyers jumps dramatically in April, but the number of listings doesn't peak until a little later, so there is less seller competition. The average list price in June is higher than April, again as larger family homes are being listed during school vacations, but there are fewer buyers, which increases the chance for a price reduction, although not by much. Homes listed in June are 1 percent more likely to see a price reduction and garner 2 percent fewer online views on average than the rest of the year.

If next week was already a great week to list, the steep drop in mortgage rates that started last week is only making it better. Buyers now have a little bit more purchasing power. The average rate on the 30-year fixed mortgage has fallen more than a quarter of a percentage point in the last week and is nearly a full point lower than the recent peak last November. Every quarter-point drop knocks about $50 off the monthly payment on a $300,000 mortgage.

Of course all real estate is local, and locality can impact timing. The best time to list in New York, Chicago and Dallas is March 31, according to realtor.com. In Atlanta and Seattle, it's April 7. In Los Angeles and Boston, it's April 14. In Phoenix and Tampa, it's early June.

And not everyone agrees. Researchers at Zillow, a competitor of realtor.com, claim the first two weeks in May are the best nationally. They add that homes listed on Saturdays get the most page views, although most real estate agents will tell you Thursday is when most people are trolling online, planning their weekend house hunts.

"Sellers time their listings to optimize their sale in all sorts of ways," said Skylar Olsen, Zillow's director of economic research and outreach. "Some need to time the sale just right to manage their own synchronized home purchase. Others are seeking to get the highest sale price possible."

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