Winter months see 14% higher mortality, with flu causing a third of 1,700 annual excess deaths
Each year as winter descends on New Zealand, the country enters a season that is both predictable and quietly devastating — a convergence of cold air, circulating viruses, and human vulnerability that claims roughly 1,700 lives in excess of what other months demand. Influenza, RSV, and the common cold are already rising in June 2026, and health experts are urging the public to meet this familiar threat with the tools that have long been shown to work: vaccination, hygiene, and the discipline to stay home when ill. The burden falls hardest on the elderly and the chronically ill, for whom a winter virus is not an inconvenience but a genuine confrontation with mortality.
- Healthline is already receiving a surge of calls about flu-like symptoms, and laboratory testing confirms RSV and the common cold are actively circulating — the seasonal wave has begun.
- New Zealand's winter months carry a 14% spike in mortality, translating to approximately 1,700 excess deaths between June and September, with influenza alone responsible for nearly a third of those losses.
- Experts warn that influenza is not a manageable inconvenience for everyone — for older adults and those with chronic conditions, it can mean hospitalisation, intensive care, or death.
- Free flu vaccinations have been available to high-risk groups since April, and health officials are urging people to combine that shot with a Covid-19 booster to address two respiratory threats simultaneously.
- Pandemic-era behaviours — distancing, covering coughs, isolating when sick — are being revived as practical, proven tools to reduce the strain on individuals and an already-pressured health system.
As June settles over New Zealand and temperatures fall, the country's health system is preparing for a surge it knows is coming. Healthline is already fielding more calls about flu-like symptoms, and the viruses appearing most frequently in testing are RSV and the common cold. The pattern is familiar — but familiarity does not diminish the stakes.
Dr. Nikki Turner of the Immunisation Advisory Centre expects conditions to worsen within weeks, calling for vaccination and a return to pandemic-era habits: keeping distance, covering coughs, and staying home when sick. The advice is not new, but it remains effective.
The deeper danger lies in the numbers. Professor Michael Baker of the University of Otago describes a 14% rise in mortality during the four coldest months, amounting to around 1,700 excess deaths each year. Influenza drives nearly a third of those deaths, with RSV and other respiratory infections accounting for much of the rest. Covid-19 adds further pressure, though without the same seasonal rhythm.
These deaths are not spread evenly across the population. They concentrate among the elderly and those managing chronic illness — people for whom, as Dr. Ji Yeon Park of the University of Auckland notes, influenza is not simply a bad cold but a potential path to hospitalisation or worse.
The most direct protection is already available. The flu vaccine — free for high-risk groups since April — offers meaningful defence against severe illness and death, and a visit for the flu shot is also a practical opportunity to update a Covid-19 booster. Whether enough people act on these options will determine how heavily the coming months weigh on New Zealand's hospitals and its communities.
As June settles over New Zealand and the temperature drops, the country's health system is bracing for what comes next: a predictable but serious surge in respiratory illness. Healthline is already fielding more calls about flu-like symptoms, and the viruses showing up most often in testing are the common cold and respiratory syncytial virus, or RSV. The pattern is familiar to anyone who has lived through a Southern Hemisphere winter, but that familiarity does not make it less consequential.
Dr. Nikki Turner, principal medical adviser at the Immunisation Advisory Centre, expects the situation to intensify within weeks. "It's usually accompanied by other nasty respiratory viruses, particularly RSV, which means we need to be prepared now to reduce the severity on individuals and communities, as well as our healthcare services," she said. The advice is straightforward: get vaccinated, and dust off the habits from the pandemic years—keep distance when you can, cover your cough, stay home when you're sick. These are not new ideas, but they work.
What makes winter dangerous in New Zealand is not just the viruses themselves, but their cumulative weight. Professor Michael Baker from the University of Otago's department of public health laid out the numbers plainly: during the four coldest months—June through September—mortality rates climb an average of 14 percent above the rest of the year. That translates to roughly 1,700 additional deaths annually. Influenza accounts for nearly a third of those excess deaths. The remainder come from other seasonal respiratory infections, with RSV playing a significant role. Covid-19 continues to add to the burden, though it does not follow a seasonal pattern.
These deaths are not distributed evenly. They concentrate among older people and those already managing chronic illness. A person in their eighties with heart disease or diabetes faces a very different winter than a healthy thirty-year-old. Dr. Ji Yeon Park from the University of Auckland emphasized that influenza is not simply a bad cold that runs its course in a few days. "Influenza can be a serious illness that leads to hospitalisation, intensive care unit admission, and sometimes death," Park said. Most people do recover quickly, but others develop serious complications that can reshape their lives or end them.
The intervention is available and free for those most at risk. Influenza vaccine has been supplied annually since April 1, and it provides solid protection against severe illness, hospitalization, and death. Baker noted that vaccination is the most direct way to prevent these outcomes. The vaccine is free for high-risk groups—the elderly, people with chronic conditions, pregnant women, and others identified as vulnerable. Getting the flu shot is also a practical moment to update a Covid-19 booster, addressing two respiratory threats at once.
What unfolds over the next few months will follow a script written by seasons and biology. The viruses are already circulating. The cold is already here. The question now is whether enough people will take the steps available to them—vaccination, basic hygiene, the willingness to stay home when sick—to blunt the edge of what is coming. The health system is watching. The numbers are waiting to be written.
Notable Quotes
Influenza can be a serious illness that leads to hospitalisation, intensive care unit admission, and sometimes death.— Dr. Ji Yeon Park, University of Auckland
In a temperate country like Aotearoa New Zealand, the winter months are always the most dangerous.— Professor Michael Baker, University of Otago
The Hearth Conversation Another angle on the story
Why does winter hit New Zealand so hard when it comes to respiratory illness? It's not like the country is in some extreme climate.
It's not about extremes—it's about the shift itself. When temperatures drop, people move indoors, spend more time in close quarters, and the viruses that thrive in cold, dry air spread more easily. The body's defenses also weaken slightly in winter. It's a perfect storm that happens every year.
And the numbers—1,700 extra deaths in four months—that's a lot. Is that surprising?
Not to the people who study it, but it should be to the rest of us. That's not a crisis that makes headlines. It's a pattern so regular we've stopped noticing it. But it's real, and it's preventable in many cases.
So why don't more people get vaccinated if it's free and it works?
Inertia, partly. Vaccination requires action—you have to remember, you have to go somewhere, you have to decide it matters. When you're healthy, it's easy to think you don't need it. The people who die are usually the ones who couldn't easily get to a clinic, or who had other things going wrong already.
Is RSV as serious as the flu?
It can be. For young children and the elderly, RSV can be just as dangerous. The difference is we have a flu vaccine but not yet a widely available RSV vaccine. That's why the experts keep mentioning it—it's coming, and we need to be ready for it.
What's the realistic outcome if people ignore this warning?
The same outcome as every winter: some people get very sick, some people die, hospitals get strained, and life goes on. It's not dramatic enough to feel urgent until it's happening to you or someone you love.