The Cancer Society's SunSmart Schools programme in Wairarapa has been hugely successful, local branch manager Anna Cardno said.
"A lot of the time when we go into schools to do the accreditation programme we find that schools are already meeting the standards.
"There's always a lot of structural as well as natural shade so the schools are really proactive in terms of planting."
Many had rules around hours of play, wearing hats and applying sunscreen, Ms Cardno said. While not all Wairarapa schools had shade sails over swimming pools, the majority that didn't either were in the process of building one or applying for grants.
The study of 189 schools looked at 12 sun-protection criteria drawn from the Cancer Society's SunSmart Schools Accreditation Programme - including shade provision, sunscreen, hats and clothing, and curriculum content.
Altogether, 57 per cent of schools said cost was an obstacle to shade development and 31 per cent to sunscreen use. Thirteen per cent reported limited support from parents.
Cancer Society SunSmart Schools programme co-ordinator Louise Sandford said there were barriers to schools implementing sun-smart initiatives.
New Zealand Principals Federation president Paul Drummond said most schools had sun-smart policies.
"It comes as a bit of a surprise that there would be large numbers of schools ignoring what is common sense ... I don't think schools need convincing."
Staying sun-smart
Slip, slop, slap and wrap.
Between 11am and 4pm in the daylight-saving months, keep children out of the direct sun.
Dress your child in a broad-brimmed hat and close-woven clothing that covers the arms, shoulders and legs.
Use a sun cover over children's pushchairs.
Use a SPF30+ broad spectrum sunscreen and reapply every two hours.
Source: SunSmart NZ