Environment Agency rainfall API
The Rainfall API provides access to these rainfall measurements, and to information on the monitoring stations providing those measurements. It is compatible with (and integrated into) the API for water level/flow readings.
To find out more about Environmental Agency API's click here: http://environment.data.gov.uk/flood-monitoring/doc/reference
Attribution: If you make use of this data please acknowledge this with the following attribution statement: this uses Environment Agency rainfall data from the real-time data API (Beta)