Rain is set to fall on two out of the three days over the Bank Holiday Weekend (August 24-26).
The Met Office forecast has Saturday as the worst day with a yellow warning of rain.
Light and heavy showers are set to fall throughout, with just a possibility of some sunshine.
As a result, the temperature will drop to just below 20degC.
At the moment Sunday is set to have sunny intervals until later in the afternoon when there could be some light showers, with temperatures up to the low 20s.
Monday looks to be the best day with plenty of sunshine all day and a high of 23degC.