But on Sunday 5.40am his time, the Australian expat is preparing to face whatever the day brings.

"I am in a house in downtown Orlando ... they have got a mandatory curfew," Mr Foster said.

"You are not allowed to go outside ... or else you get arrested, because a lot of people have vacated their homes and relocated to schools around here."

Hurricane Irma was due to pass directly overhead, but shifted west to Tampa, about an hour from where Mr Foster lives.

The effects of one of the biggest cyclons to ever hit the Atlantic will, however, be felt in the neighbourhood.

"There is a lot of trees in this areas that are likely to come down or bring power lines down with them," he said.

"Right now there is a risk of tornadoes on the outskirts of the hurricane.

"It is going to start getting really bad at 2pm today (early Monday, AEST), just escalating throughout the night."

And if the winds get above 120km/h, there is a chance he might lose the roof of his house.

Mr Foster, and, he said, many of his neighbours, had decided to stay put, some boarding up their windows to guard against the wind.

But in case of an emergency evacuation, Mr Foster had his passport and other essentials ready to go. Friends and family in Perth and Melbourne have all been in touch.

"I am expecting to lose power for three to seven days," he said.

He said he had packed a cooler, has plenty of water stored and filled his car with petrol, but the shops had run out of everything by the middle of last week.

"Middle of the week the shops ran out of everything. I have got lots of water and a full tank of gas. We'll see what happens afterwards ."

Florida residents, he said, were quite stoic about the situation, having lived through other hurricanes before, though of a lesser intensity,

"Florida people are fairly casual," he said.

"It is a matter of just getting on and dealing with it. There is not much you can do. Just lock everything down and hope for the best.

Mr Foster said he had missed out on buying a generator as they had all sold out, but, despite everything, he wasn't scared.

"Until it actually starts, it doesn't seem quite real, or you don't know how bad it's going to be," he said.

"I haven't been in 60 to 100 miles/h winds (up to 160km/h) before."

Down on the west coast, on Friday about 10pm (Saturday afternoon, AEST), Melburnian Tahra Lehman, her American husband, Scott, and children, Madison, 12, and Jacob, 9, all had to evacuate their home in Cape Coral, Florida.

They secured their house and put metal shutters over the windows, hoping it will withstand the fury of the storm - enough for them to have a home to return to in a week's time.

"We secured the house, packed up an SUV filled with clothes and belongings and headed to the other side...north-east Florida for safety," Ms Lehman said.

"Our concern was running out of gas and finding a hotel room but someone was looking over us. We found everything we needed."

Further up the coast, closer to Tampa, it is early hours of the Sunday morning (Sunday night, AEST) and Lakewood Ranch Medical Centre's chief operating officer Chris Loftus hasn't slept for 18 hours.

Once the storm hits he expects to be at the hospital for at least a week.

"Right now it is a very slow time because we are prepping up for the storm," Mr Loftus said.

"People have been for quite a while at the hospital, so a lot of people are resting, sleeping as much as they can."

All night they helped evacuate some of the most acute patients from their sister concern, Manatee Memorial Hospital, which was closer to the coastline.

Now their numbers have swelled to100 patients and 200 staff.

They have food, fuel, water to survive the next 96-hours without help. There is generators to supply back up power. The building itself is constructed to withstand the hurricane.

"Af of right now, the projections have shown the eye of the hurricane goes directly over us. We will 100 per cent be getting impacted," Mr Loftus said.

"What you will find in healthcare, you have a lot of dedicated people who got into this profession because they like helping people.

"The mood is we will get through this together ... and we are ready for anything thrown at us and we'll be here to serve our community."