A 'danger to life' warning was issued on Saturday as Storm Antoni hit parts of the UK, bringing heavy rain and strong winds.
Falling trees and riptides were among the hazards the Met Office warned of, along with the risk of potentially fatal injuries from flying debris, in the alert covering south-western areas of Britain.
Met Office meteorologist Tom Morgan said the storm, the first the forecaster has named this season, could see winds of up to 110kph on the coast and 96kph inland.
“For August this is very unusual,” he said.
“With it being the holiday season and it being a Saturday there will be plenty of local events going on.
“Effectively the trees are in full leaf so are more susceptible to strong winds.
“Building structures, trees and temporary structures such as marquees may not be too adequate.
“Beach debris could be thrown from waves on to coastal roads, there's a risk of dangerous tides, riptides and power cuts. Most travel disruption will be from trees and branches.”
Saturday would also feel “unseasonably chilly” with some areas not rising above 15°C, and highs of 19°C or 20°C on the south coast, Mr Morgan added.
But Sunday was set to be brighter and less windy with no weather warnings in place, and temperatures of up to 22°C in the south.
Temperatures will start to rise next week, reaching a peak of 27°C or 28°C on Thursday in the south-east, highs that have not been seen in the UK since June, the forecaster added.
The RAC estimated that about four million cars would be using British roads for leisure journeys across the whole weekend.
Eliot Walker, organiser of the annual Dorset jazz festival, Stompin' On The Quomps, said he was “disappointed” he had to postpone this year's event due to Storm Antoni.
The free festival in Christchurch Quay was forced to cancel its activities for the first time in its 30-year history. Around 10,000 people had been expected to attend on Saturday.
The decision was driven by concerns for the safety of traders and spectators although it is hoped the festival can be rearranged.
“We're really disappointed that the town can't come together to enjoy a wonderful day listening to professional jazz and big bands by the side of the river on the picturesque quay,” Mr Walker said.