Today's UV index in San Francisco, United States will be up to 5, indicating moderate risk of harm from the sun's UV rays for the average person.
A UV index reading of 3 to 5 indicates a moderate risk of harm from unprotected sun exposure.
The UV index in San Francisco will be up to 5 today, so it's best to stay in the shade during midday when the sun is strongest.
If you need to be outdoors, wear sun protective clothing, a wide-brimmed hat, and UV-blocking sunglasses.
It's important to generously apply broad-spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days and after swimming or sweating.
Keep in mind that bright surfaces like sand, water, and snow can increase UV exposure, so take extra care in these environments.