Dorset Council has issued a warning ahead of the weekend when temperatures are set to soar, appealing to people visiting beaches to take extra precautions as rockfalls will be more likely.
They say the risk is even greater than usual along the World Heritage coastline as heat causes rocks to expand and with fluctuating temperatures pre-existing cracks can widen. This makes the cliffs more unstable.
Portfolio holder for highways, travel and environment Cllr Ray Bryan said: “Rockfalls are entirely unpredictable and can happen at any time, but we do know which conditions make them more likely, and prolonged hot and dry spells are one of them.
Watch major rockfall at West Bay last year
“We would encourage anyone thinking of visiting the Dorset coast during this heatwave to stay away from the base of cliffs, and if you are walking along the coast paths, keep well away from the edges.
"Never ignore a warning sign – they are there for your safety. It is easy to enjoy the spectacular and fascinating Jurassic Coast without putting yourself or others at risk.”
Where are rock falls most likely on the Dorset coastline?
The council has identified a number of areas where the risk of potential rockfalls is particularly acute. They are cliffs around Seatown, Eype, Burton Bradstock, West Cliff, East Cliff, Mupe Bay, Lulworth and Swanage.
Catherine Pennington, Landslide specialist at the British Geological Survey, said: “Landslides can occur on our dynamic coast at any time and the science research to fully understand the link between rockfalls and temperature fluctuations is still ongoing.
“What we do know is that cracks can form or widen during these changes in temperature.
"In general, cracks related to instability can be very difficult to see from the cliff top, as can unsupported, overhanging rocks so, as well as staying well away from the cliffs on the beach, it is also important to stay away from cliff edges at the top.”