Organisers at Osborne House say they're reviewing the state of the ground daily ahead of next weekend's gigs.
Steps are due to perform there on Saturday 28th, while Tom Jones is set to play on Sunday 29th of July.
In a statement, English Heritage said it is 'continuing to monitor the weather and the condition of the Durbar Lawn next to Osborne House with a view to decided whether the ground is too waterlogged to build and stage the two concerts safely.
'The Bournemouth Symphony Orchestra Concert on 21 July has been cancelled', it adds.
The statement comes after a live Blue Peter show, due to be filmed at Osborne House on Saturday 14th July to co-incide with the Olympic Torch's arrival there, was cancelled due to saturated ground.
A decision on the Steps and Tom Jones concerts is expected by the end of this week.