Wellington Hospital's Emergency Department had its busiest day for almost a year on Monday, seeing a total of 258 patients.

Health NZ said this compared with an average of 189 a day last month.

But it added as a caveat that the data was operational and was subject to change following a a quality assurance process.

The agency said there had been high demand over the last few days and some staff sickness.

Robert Blaikie, interim deputy group director of operations, said winter was a busy time for healthcare providers.

"Despite these pressures, our dedicated staff continued to provide safe, compassionate and professional care in extremely difficult circumstances. I would like to thank them for their dedication and professionalism."

He said staff had increased temporary capacity and frequently reviewed patients to see if they might be discharged sooner.

He said preparations for winter had been underway since March, including more staff, beds and community care.

The capital's urgent care clinic's opening hours are being extended to give patients alternative options.

A specialised elderly care nurse will support earlier discharge for senior patients in the Hutt Valley.

A nurse will be introduced to a pharmacy in Porirua and four in the Hutt Valley.

Health NZ advised the public to get their flu and whooping cough jabs to protect themsleves and the wider community.

It encouraged people to consider other options for care, including Healthline, local GPs and pharmacies.