The higher fees would also help fund the rising maintenance and lighting costs, the spokesperson added.
Previously, the trust charged a flat £5 for parking between two and 24 hours but this will now rise to £6.30 for two to four hours, and £7 for four to 24 hours.
Short-term permits cost £35 for the first week, then £7 for each week after.
The increases are the first since 2016 and will align parking charges with those as Goole and District Hospital, Scunthorpe General Hospital, and Diana, Princess of Wales Hospital in Grimsby.
Parking will remain free for cancer patients, blue badge holders, parents or guardians of children staying overnight, and the families or next of kin of those receiving palliative care.
Patients who regularly attend outpatient appointments may also be eligible to claim back the cost of their parking.
