Slather on top-rated sunscreens before you head to the pool this weekend

With temps rising into the 90s and plenty of sunshine, the forecast is calling people to get outside, but if you're heading to the pool or beach, you'll need sunscreen.

Consumer Reports just released the results of its annual sunscreen tests. The magazine tested many of the top brands to help find the products that will best protect your skin.

One of the things testers looked for is SPF rating, a measure of how well a sunscreen guards against ultraviolet B rays from the sun. Those are the chief cause of sunburn and a contributor to skin cancer.

"In our sunscreen tests, we found that many sunscreens don't meet the SPF level printed on the package," said Consumer Reports' Susan Booth. "So, Consumer Reports recommends buying a chemical sunscreen with an SPF 40 or higher."

Two of the magazine's top-rated sunscreens are Equate Walmart Sport Lotion SPF 50 and Trader Joe's Spray SPF 50.

If you're looking for a sunscreen that has mineral ingredients, thinking it has fewer chemicals, Booth says to shop carefully.

"In our sunscreen tests in recent years, we haven't found a mineral sunscreen that provides both top-notch protection and meets its labeled SPF," Booth said.

Booth also said sunscreens labeled "water resistant" are not waterproof. As soon as you start to sweat or get in the water,  the sunscreen starts to come off.

For the best protection, Consumer Reports says to apply sunscreen 15 minutes before you go out, then reapply every two hours, and don't forget to cover your ears, the backs of your hands and the tops of your feet.

Consumer Reports says you should use one teaspoon of sunscreen per body part or area.

And what about half-used sunscreen you have from last year?

Consumer Reports says sunscreen is formulated to remain effective for at least three years. Health experts say you should toss anything beyond its labeled expiration date.