Weather warnings have been issued today as a result of the tropical storm Bertha.
Downpours on Sunday could see up to 50mm of rain fall over the course of the day.
There is a second weather warning in place for today, with heavy downpours forecast for parts of south west Hertfordshire.
The Environment Agency said heavy rain may lead to surface water flooding and has advised people to regularly check the flood risk situation over the next 48 hours.
The warning is in place from 12.15am until 11.45pm on Sunday.