With that opportunity to celebrate the place in which we live, we need to remember that solar radiation is at its most intense in July in North America, according to UV index average values.
What does that mean for you? Put on the sunscreen, because overexposure brings with it a risk of skin cancer. And limit your exposure between 10 a.m. and 4 p.m., when solar radiation is its most intense.

And your grandma was right: You can get a sunburn on an overcast day, since UVB rays are only partially blocked by clouds.
In fact, according to the Skin Cancer Foundation up to 80 percent of UV rays can pass through clouds.
The amount of UVB in sunlight can vary by season, location and time of day. However, UVA radiation is always around during the day.