More new cases of skin cancer are diagnosed every year than all other types of cancer combined. There's no indication that the skin cancer epidemic has peaked. Though most such cancers can be treated and cured, some cases can be fatal.

That's why the Weather Service is to be applauded for starting this week to add a solar-hazard rating to the daily weather report. A prime cause of skin cancer is exposure to the sun's ultraviolet rays, which also can pose dangers to the eyes and the immune system.But it's not enough to look at the daily solar-hazard rating and apply an extra dollop of sunscreen lotion when the readings are high. The latest word from researchers is that some sunscreen lotions may not prevent malignant melanoma, the sometimes fatal form of skin cancer.

Nor is it prudent to assume the risk is reduced whenever the skies are cloudy. Thick, heavy clouds do indeed block most of the ultraviolet rays. But high, thin cirrus clouds may make it only seem less sunny while letting through dangerous amounts of ultraviolet light.

That goes particularly for Utah, where the latitude and high altitude increase the risks from overexposure to the sun.

Keep in mind, too, that different types and colors of skin react differently to ultraviolet radiation.

The safest strategy is to wear a hat and protective clothing, stay in the shade, use sunglasses and don't sunbathe during the peak hours for ultraviolet light of between 10 a.m. and 3 p.m. It's also only common sense to avoid tanning parlors and sunlamps.

Besides minimizing exposure to the sun, it's also a good idea to examine one's skin regularly for changes in moles, freckles and discolorations.

In other words, the new solar-hazard rating in the daily weather report is like any other useful tool: It is no more effective than the extent to which it is used regularly and effectively.