Flooding has been causing a telephone fault at Dewsbury and District Hospital.
Mid Yorkshire Hospitals NHS Trust said floods in Leeds city centre had affected the Vodafone telephone exchange used by the hospital.
Some external phone lines are not connecting to the Halifax Road hospital’s usual number.
People who need to contact Dewsbury hospital are being asked to dial 01924 542801 and ask for the department they need.
Mid Yorkshire said: “We apologise for any inconvenience.”