Few things feel more Kiwi than a summer spent outdoors. But the same clear skies that make our summers so good also make our sun unusually harsh, and burns can happen faster than many of us expect. The good news is that skin cancer is largely preventable, and a few simple habits make a big difference.
Why Kiwis need to take extra care
Skin cancer is New Zealand’s most common cancer by a long way. There are about 97,000 new skin cancers a year, compared with around 25,000 for all other cancers combined. A 2022 study in JAMA Dermatology found New Zealand had the world’s highest death rate from melanoma in 2020, ahead of Australia, and 333 New Zealanders died from melanoma in 2021.
So why is our sun so harsh? NIWA scientist Dr Richard McKenzie points to three reasons our summer UV is stronger than at similar latitudes in the northern hemisphere: much clearer skies (about a 20% effect), lower ozone in summer (about 10%) and Earth being closer to the sun in our summer (about 7%). Add in a large fair-skinned population and a love of the outdoors, and the risk adds up.
The upside? More than 90% of skin cancers in New Zealand are linked to too much UV, which means most are preventable.
Know when to cover up
Health New Zealand advises avoiding the sun between 10am and 4pm from September to April, and whenever UV levels are 3 or higher. That’s when the sun’s ultraviolet (UV) rays are strongest.
Crucially, UV isn’t the same as heat. You can’t see or feel it, and you can still get burnt on a cool or cloudy day. So rather than going by the temperature, check the UV Index (UVI):
- UVI 3–5 (moderate): protection needed.
- UVI 6–7 (high): stay in the shade between 10am and 4pm, and cover up.
- UVI 8–10 (very high): plan outdoor activities for early morning or evening, and use full protection.
That’s the Cancer Society’s guide to the UV Index. The Cancer Society’s free UVNZ app uses NIWA data to tell you when you need protection where you are. In winter, you’ll still need protection at high altitude, such as when skiing or tramping.
Slip, slop, slap and wrap
The old advice still works. Here’s how to get it right.
- Seek shade. Good-quality shade can cut UV exposure by up to 75%, according to the Cancer Society.
- Slip on clothing that covers as much skin as possible, such as a long-sleeved shirt with a collar.
- Slop on sunscreen. Choose a broad-spectrum, water-resistant sunscreen of at least SPF 30.
- Slap on a hat with a wide brim that shades your face, ears and neck.
- Wrap on sunglasses. Not all sunglasses block UV, so look for ones that meet the Australian/New Zealand Standard AS/NZS 1067:2016.
Are you using enough sunscreen?
Most of us don’t put on nearly enough. SunSmart says the average adult needs about seven teaspoons of sunscreen to cover their whole body. Apply it 20 minutes before you head outside, so it has time to bind to your skin. Yet only 38% of people do. Then reapply every two hours, and straight after swimming or sweating, even if the label says it lasts four hours.
The good news is that the bottle in your beach bag is more trustworthy than it used to be. Since 2022, the Sunscreen (Product Safety Standard) Act has made the AS/NZS 2604:2012 standard mandatory for sunscreens sold in New Zealand, so products must be tested to meet their claims.
What about vitamin D?
It’s a common worry, but Health New Zealand says wearing sunscreen when it’s needed does not stop you making enough vitamin D. And skip the sunbeds: the Cancer Society advises against them, and it’s illegal for under-18s to use commercial sunbeds.
Check your skin
Caught early, most skin cancers can be treated successfully, so getting to know your skin is one of the best habits you can build. Healthify recommends checking your skin about every three months, from top to toe. Use a mirror, or ask someone to help with hard-to-see spots like your back and scalp. Melanomas can appear anywhere, not only on skin that’s been in the sun.
Don’t just watch your existing moles, either. Two-thirds of melanomas appear as a new spot rather than in an existing mole.
When you check, think ABCDE:
- A – Asymmetry: one half doesn’t match the other.
- B – Border: the edges are uneven, blurred or jagged.
- C – Colour: the spot has several colours, or uneven colour.
- D – Diameter: the spot is growing, or larger than about 6mm.
- E – Evolving: the spot is new, or has changed since you last checked.
Melanoma New Zealand adds F and G: a spot that is firm to the touch, or growing. Also watch for an “ugly duckling”, a spot that looks different from all your others.
If you notice anything new, changing or unusual, see your GP. Don’t wait to see if it goes away.
Where to get help
- Your GP can give you a full-body skin check and refer you on if needed.
- Melanoma New Zealand runs free spot checks with nurse educators around the country, and free online or phone consultations. Visit melanoma.org.nz to find out where its spot check van is heading next.
- Cancer Society’s Cancer Information Helpline: 0800 226 237, for free advice from a cancer nurse.
- Healthline: 0800 611 116, free health advice 24 hours a day.
- SunSmart: sunsmart.org.nz, for sun safety tips and the free UVNZ app.
