A Flood Alert has been issued by the Environment Agency for the River Cherwell from Lower Heyford down to and including Oxford.
The agency warns that low lying land and roads will be affected first.
The river and flooding forecast is: the River Cherwell has responded to the rainfall which fell on Wednesday night and throughout the day and spilled out into the floodplain. River levels were expected to continue to slowly rise overnight. No property flooding is currently expected.
"The weather prospects are: further rainfall is expected on Thursday, and a band of heavy persistent showers are forecast to bring further rainfall at the weekend."