The Met Office has issued a severe weather warning of heavy rain for Hull and the East Riding.
Outbreaks of heavy rain are expected throughout Saturday, beginning in the early hours.
The worst of the weather is forecast to hit Hull between 1am and 10am.
A Met Office spokesman said: "An area of low pressure is expected to move westwards across central parts of the UK from the North Sea on Saturday.
"This will contain some very moist air and is likely to generate some heavy rainfall.
"The heaviest rainfall is likely to occur during the morning before easing in places during the afternoon and then finally dying out during the evening.
"There is currently some uncertainty over the track of the area of low pressure and therefore also the extent of the heavy rain, with the greatest uncertainty over the southern boundary of the yellow area.
"This warning may be updated later Friday or early Saturday, hence the public are advised to stay in touch with the latest forecasts."
