The Met Office has issued a yellow weather warning for thunderstorms for parts of England.
It said a band of heavy rain and thunderstorms was moving north from Devon and Dorset, across to Somerset, Bristol, Gloucestershire, Wiltshire and then to parts of Wales and the West Midlands.
Between 12:00 and 16:00 BST some places could have between 20-30mm of rain.
There could also be a risk of flooding in some areas, the Met Office added. It advised people in flood risk areas to be prepared.