PUNTA GORDA, Fla. (AP) -- Storm-weary Floridians kept an anxious eye on Hurricane Wilma as it grew into a monster Category 5 storm Wednesday, with forecasters warning of a significant threat to the state by the weekend.

The storm was expected to strengthen on a path that could threaten coastal areas like Punta Gorda in southwestern Florida that were hit by Charley, a Category 4 storm that was the first of six hurricanes to strike the state since August 2004.

Gov. Jeb Bush said Floridians must be thinking, ''Why us? ... It's just something we're going to have to live with and prepare for.''

Many residents said they take every storm seriously now, after witnessing the devastation from Katrina and other storms that have ravaged the southern United States.

''People have learned their lesson and know better how to prepare. We're not waiting till the last minute anymore,'' said Andrea Yerger, 48, of Port Charlotte. She was buying material to fix and protect her house, which had to be gutted after of last year's Hurricane Charley.

Charley was the first of six hurricanes to strike the state since August 2004, causing more than $20 billion and killing nearly 150 people.

Wilma became a Category 5 hurricane early Wednesday with 175 mph wind, according to the National Hurricane Center in Miami. A key reading of the storm's pressure showed it to be the most powerful of the year.

''It does look like it poses a significant threat to Florida by the weekend. Of course, these are four- and five-day forecasts, so things can change,'' said Dan Brown, a meteorologist at the National Hurricane Center.

The state routinely replenishes emergency supplies of water, food and ice at staging points across Florida, so no additional action is needed, emergency management spokesman Mike Stone said.

Many Punta Gorda homes and businesses have been rebuilt in a construction boom, but some are still boarded up. More than 6,800 federal trailers and mobile homes remain scattered around the state as temporary housing from the six storms, with 934 in Charlotte County alone.

Florida supermarkets and home-repair chains stocked extra food, ice and other supplies ahead of an expected onslaught in stores.

''I think since Katrina, everyone is more apprehensive about the situation as far as hurricanes go,'' said Pat Schmidt, 74, a retiree from Port Charlotte who was buying jugs of water and canned goods at a supermarket.

By 2 a.m. EDT, the hurricane was centered about 170 miles southwest of Grand Cayman Island and about 400 miles southeast of Cozumel, Mexico. It was moving toward the west-northwest at nearly 8 mph, according to the Hurricane Center.

Wilma made history before hitting land. It is the 12th hurricane of the season, the same number reached in 1969, the highest since record-keeping began in 1851. It is also the 21st named storm, tying the record set in 1933.

The six-month hurricane season ends Nov. 30. Wilma is the last on the 21-name list for storms this year. If any other storms form, letters from the Greek alphabet would be used for the first time, starting with Alpha.

So far this year, the Atlantic has had as many hurricanes as in two normal seasons. There are 10 tropical storms and six hurricanes in the average season.

''I hope people aren't too worried. It's not time to panic. It's time to prepare,'' said Sandra Mallory, 68, of Port Charlotte.