New Zealanders are being asked to alert northern hemisphere Rugby World Cup visitors to the risk of sunburn.
The Cancer Society is urging all those associated with the RWC who will be in contact with visitors to remind them of the "Slip, Slop, Slap and Wrap" message.
The society's national health promotion manager Dr Jan Pearson said the major concern was that thousands of people, especially those from the northern hemisphere, did not know how fierce the sun could be in New Zealand.
Ultraviolet radiation peak levels in New Zealand during daylight saving months were 40% higher than places at similar latitudes in the northern hemisphere, she said.
Daylight saving begins this weekend, on September 25.
Cancer Society Otago-Southland division health promotion manager Penelope Scott said UV index levels were still within the safe range of about 2, but were beginning to rise. By the end of the month, people outside for most of the day could get sunburnt.
She recalled a year when her nephew got sunburnt on September 17 after a day tailing lambs.
The higher the UV level, the quicker people got burnt, she said.
It was also important to remember UV radiation was not related to sensation of heat. People could still get burnt on cooler, cloudy days if the UV was 3 or more on the index.
The UV levels are recorded in five places around the country, including Lauder, in Central Otago, and Invercargill.
Average monthly levels show that in Central Otago the only time sun protection is not required is from April to July, while in Invercargill it is from April to September.
Sun-smart message
• Slip on sun-protective clothing.
• Slop on sunscreen with a SPF 30+ rating and repeat two-hourly.
• Slap on a hat, protecting your face, head, neck and ears.
• Seek shade whenever possible.
• Wrap on some sunglasses which meet the Australian-New Zealand standard.
• Peak UV time is 11am-4pm.
• Those with fair skin are more at risk.