The Met Office issued a yellow weather warning for Saturday, with poor weather expected across the south of England and Wales. Flooding, thunderstorms and gusts of wind up to 55mph have been predicted.
The British Holiday and Home Parks Association estimated 90 percent of sites are now fully booked for the next week.
Despite this, many are opening between only 60 and 80 percent of their pitches to maintain social distancing.
Visit Britain said 16.4 million UK adults plan to take an overnight domestic trip this summer.
It is estimated that 33 percent are planning on camping or caravanning, equating to 5.4million people.
Thunderstorms were forecast to move into southern England overnight, reaching south Wales and the Midlands early on Saturday.
Frequent lightning and the possibility of large hailstones falling as well as torrential rainfall were likely, the Met Office said.
As a result of the ever-changing rules on travel abroad, many will be taking a break within the UK.
According to RAC research, around 55 percent of holidaymakers will be driving more than 150 miles.
A further 17 percent will be travelling more than 300 miles from home, showing an increased amount of people are wanting to explore parts of the UK.
The survey also found that a staggering 90 percent of trips will be made by personal transport, with the remaining ten percent using a caravan or motorhome.
However, they are warning of “unprecedented” levels of traffic this summer as people look for an escape as lockdown restrictions ease.
Drivers should also do their best to check traffic conditions and avoid travelling on the busiest roads during peak hours.