It's going to be a sunny and warm Memorial Day weekend. It will be a great time to enjoy the outdoors, wearing sunscreen of course.
The UV Index gives us an idea of how strong UV radiation will be. There are three different kinds of UV radiation: UV A, UV B, and UV C.
The third one is absorbed by ozone and is the most damaging. UV A and UV B is still able to get through the atmosphere and cause a sun burn.
The UV Index looks at the amount of ozone, cloud cover, and elevation. Higher elevations don't absorb as much radiation as lower elevations. Which means you are more likely to get a sunburn at Tahoe than you are in Reno.
Snow, water, and sand can also double the strength of UV radiation. Not only can sunscreen wash off, but the water also increases your chances of getting burnt to begin with.
The UV Index is very high for Reno and Tahoe this weekend, especially on Sunday. The UV Index is for when the sun will be at it's peak, usually around midday. It's best to seek shade from about 10:00 a.m. through 4:00 p.m., when the sun is at it's highest angle in the sky.
For Sunday, the UV Index is expected to be around a nine in Reno, but up to a ten in the southern Sierra. Thanks to some clouds, the UV Index goes down some - especially in the Sierra around Tahoe - on Monday. However, there will not be enough cloud cover to eliminate the threat of getting a sunburn completely.
UV radiation is emitted by the sun, and travels through the atmosphere as non-visible light. The ozone is able to absorb some of the radiation but not all of it.
Anything above a level two means you need sunscreen. Anything above a seven needs added protection, beyond sunscreen.
