According to NSW Health, the state has had its worst season since a pandemic in 2009, but in Murrumbidgee the number of flu cases this year is proving to be "pretty much" the highest on record.

"For Murrumbidgee for flu presentations, we've actually seen a higher number in our area than on record, pretty much," Murrumbidgee director of public health Tracey Oakman said.

"We peaked in terms of presentations in the second week of July. That was our busiest time, but it has been still at a raised level pretty much since early June."

The high number of cases comes despite record numbers of Australians - about 13 million - being vaccinated.

"This was a record number, up from 11 million in 2018," a spokesman for the Pharmacy Guild told The Daily Advertiser. "Imagine how much worse it could have been if those people hadn't been vaccinated."

In June, Wagga's pharmacies and and many clinics were hit by a temporary shortage in flu vaccine, which left would-be patients waiting up to two weeks for their dose.

The 2019 flu season began earlier than expected, with a report by the World Health Organisation Influenza Centre describing the outbreak as "exceptional", as researchers try to establish why.

Official figures for the just week ending September 1, show there were 5417 notifications of flu in NSW, down from the previous week's 6240. There have been 96,325 notifications so far this year.

In that same week, there were 276 cases reported across the Murrumbidgee region, down slightly from the previous 289.

The highest number of cases reported in Murrumbidgee in a seven-day period was 385 cases in the week ending July 14.

The flu season is being blamed for a hike in the number of people visiting the state's hospital emergency rooms.

NSW Health acting deputy secretary Elizabeth Wood said for the second successive quarter the patient numbers were the highest of any other previous one on record and the flu is partially to blame.

At Wagga Base Hospital, there was an increase of 10.9 per cent in the number of people visiting the emergency department in April, May and June compared to the same period in 2018.