More ambulances are waiting over 30 minutes outside A&E for patient handover, figures show.
The percentage of 999 arrivals who waited more than 30 minutes in an ambulance before being handed over to Northern General staff rose from three per cent to nine per cent comparing October 2017 and November. 2017. The NHS target time is 15 minutes.
The number of patients who were transferred into A&E within the 15 minute time frame fell from 83 per cent to 70 per cent.
In October, there were five handovers that took longer than 60 minutes.
Sheffield hospital bosses said there has been a 'considerable increase' in emergency patients coming through A&E by ambulance.
Ambulance chiefs also said emergency departments across the country have seen 'very high demand' which has resulted in delayed handovers.
NHS bosses in Sheffield have implemented a new ambulance handover mode to improve patient care and flow through the department. This is under a process of 'continuous review and improvement'.
Kirsten Major, deputy chief executive at Sheffield Teaching Hospitals NHS Foundation Trust: “Up until November, over 80 per cent of all handovers from ambulance staff to our emergency department team were taking place within 15 minutes and less than four per cent took longer than 30 minutes.
"However since the beginning of winter there has been a considerable increase in the number of emergency patients coming into A&E and many have come by ambulance.
"Whilst our A&E teams have worked exceptionally hard to try and limit the time ambulance crews wait in the department, the higher than normal number of patients as well as the rise in the average level of sickness of these patients arriving into the department has meant that some handovers have taken a little longer than 15 minutes.
"We are continuing to work with ambulance colleagues to do all we can to improve the handover time as the winter demand subsides.”
Steve Rendi, Sector Commander of A&E Operations South Yorkshire at Yorkshire Ambulance Service NHS Trust, said: “Effective handovers from the ambulance service to hospital emergency departments are an integral part of delivering the best clinical care for patients.
"Our staff work tirelessly to respond to 999 calls and we continue to work together closely with hospital colleagues to ensure efficient ambulance handover processes are in place.
"Many hospital emergency departments across the country have experienced very high demand during the winter months which, understandably, has resulted in delayed handovers.
"Yorkshire Ambulance Service continues to liaise with hospitals and other NHS partners in Yorkshire and the Humber to try to resolve any issues and minimise the impact on patients.”