NEW YORK (CNN/Money) - The red-hot U.S. housing market, after a typical summer slowdown, has taken off again and Hurricane Katrina contributed to up-ticks in several localities.

According to the National Association of Realtors, with inventory of homes available for sale across the country so tight anyway, rebuilding the Gulf Coast will place additional pressure on all home prices.

"New home prices will be immediately impacted because of increased construction costs," says NAR economist Lawrence Yun, "and that will filter down to existing home prices as well." That's because as new house prices rise, more homebuyers will consider existing homes, increasing the demand (and prices) for them.

Home sales have already spiked, as has rental demand, in regions surrounding the disaster zone in the Gulf Coast, according to NAR.

Michael Carliner, economist with the National Association of Home Builders, points to increased housing demand in Baton Rouge and Houston, which pre-Katrina, had a large inventory of vacant rental housing. Much of that has now been snapped up, he said.

In Baton Rouge, evacuees have bid up property values by up to 30 percent in just the last week or two. (See that story here.)

But it isn't just a Katrina effect. With home prices having gained so much in the past few years, skeptics have been waiting for what they consider to be an inevitable slowdown, and were quick to point to sluggish activity over the summer.

Those skeptics are still worried, but for the time being, there already are signs that the rally is picking up where it left off.

Katrina has had little effect on neighboring Florida markets, except for a trickle of hurricane evacuees in the panhandle area. Some businesses have also temporarily relocated to Tampa and other Florida towns, putting a little more pressure on markets.

Overall though, Sunshine State markets have continued strong and high prices are transforming landscapes. As single-family home costs have exceeded affordability for many Floridians, condo sales have boomed.

That has, in turn, affected the rental market -- investors are snapping up apartment buildings for condo conversion and sending their prices climbing.

Said Matthew Martinez, who owns rental properties in Boston and Florida: "I've looked at 22 apartment buildings in Miami in the past two weeks and bought none. The economics just don't make sense anymore."

Just north of Miami, the situation is much the same. Elena Felipa, vice president of the Corcoron Group in West Palm, said "Lots of apartments are being converted to condos," she says. "There are few rentals around anymore."

Felipa says many recently constructed rental buildings – some just a year or two old – are already undergoing condo conversion.

Area prices have hit $350 a square foot – off the water – and $1,000 a square foot or more for waterfront property, according to Felipa.

That has driven bargain seekers three hours north to the Daytona area, where condos on the Intercoastal Waterway can still be had for $400,000 or $500,000. "You can't touch that in south Florida," said Felipa.

Manhattan is about as far removed from the disaster in the Delta as one can get in the United States. But the market revitalized during late summer as well, after it paused to catch its breath in July, according to Corcoron's CEO Pam Liebman.

"What we're seeing is that fall is off to a running start, a sprint really," said Liebman. She credits talk of interest rates stabilizing (a possible Katrina effect) for triggering the new "burst of buying, especially in entry level apartments," which in Gotham often means million-dollar, one-bedroom co-ops.

Manhattan's other consistently strong suit this year has been high-end properties. "We have seen very strong buys from the superwealthy, especially hedge fund operators. This year we had more transactions above $10 million than ever," said Liebman.

The wealthy are also out in force on Long Island beach communities, according to Liebman. "In the Hamptons," she says, "the biggest problem is a lack of inventory. Everything available is getting snapped up."

The most expensive homes there, of course, are on the oceanfront. "Near or on the ocean, you're practically setting your own price," she says.

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Prices for houses in the Bay Area keep rising. Read more here.

Freddie Mac is suspending mortgage payment collections for hurricane victims. See that story here.

Some buyers are waiting for the bubble to pop. Good idea? Ask the expert.