Waikato hospital is so overloaded with patients it had to discharge triple the usual number of people in one day to help free up bed space.
Over the weekend, the hospital experienced an influx of patients from the emergency department.
Clinical director Doug Stephenson said many of those needed to stay on into Monday and Tuesday, which meant there were no free beds for new patients.
There were 40 patients in the emergency department at 7am on Tuesday morning needing to be admitted to the hospital, he said.
Dr Stephenson said the crisis was now over and Waikato Hospital's normal services had resumed.
"Yesterday morning we had 42 patients in our ED waiting to get to a bed. As of this morning we have one patient.
"When you get those cold blasts you definitely get an influx of patients and that's what happened to us over the weekend and into Monday."
However, patients who could safely be discharged yesterday were sent home and all elective surgeries postponed.
Dr Stephson said that kind of situation put the hospital into crisis mode.
"If we have to cancel our elective surgery schedule or reschedule ... to us that's a crisis. We have patients that need those surgeries done and we don't want to have to interfere with those schedules," he said.
Dr Stephenson said the wintery cold snap was being blamed for the influx of patients because it caused problems for people with respiratory issues and triggered other viruses.
GPs and patients were very understanding about the lack of beds, he said.