Shadow test

If you're not sure if the SUN rays are safe, do the shadow test to make an on-the-spot Ultra Violet (UV) estimate. Just look at your shadow if you can't see it at all, dangerous UV rays are reaching you. If your shadow is shorter than you are, you're in high territory. If it extends way out beyond you, you'er somewhat safer from UV rays, although UV rays remain in effect all day, every day.