The Met Office has warned the UK will be battered by heavy rains and thunderstorms, and issued a severe Yellow warning.
The weather warnings will be in place until Thursday, and the dire weather could cause travel chaos for thousands, according to reports.
“Where flooding occurs, there is a slight chance of delays or cancellations to train and bus services,” the Met Office warned as quoted by the Express.
Heavy rain is expected to hit east and southeast England at first, and it later it could spread slowly to north and west through the day to reach parts of Wales and northern England.
Up to 50mm of rainfall is predicted to hit some parts of the UK.