The ozone layer shields the Earth from harmful UV radiation. Ozone depletion, as well as seasonal and weather variations, cause different amounts of UV radiation to reach the Earth at any given time. This UV-Index forecast uses the KNMI/EMA multi-day UV-Index forecast which predicts radiation levels on a 1-11+ scale, based on latitude and longitude of the location.

2            2 or less: Low

A UV Index reading of 2 or less means low danger from the sun's UV rays for the average person:

• Wear sunglasses on bright days. In winter, reflection off snow can nearly double UV strength.
• If you burn easily, cover up and use sunscreen.

3            3 - 5: Moderate

A UV Index reading of 3 to 5 means moderate risk of harm from unprotected sun exposure.

• Take precautions, such as covering up, if you will be outside.
• Stay in shade near midday when the sun is strongest.

Me and My Shadow

An easy way to tell how much UV exposure you are getting is to look for your shadow:

• If your shadow is taller than you are (in the early morning and late afternoon), your UV exposure is likely to be low.
• If your shadow is shorter than you are (around midday), you are being exposed to high levels of UV radiation. Seek shade and protect your skin and eyes.

4            6 - 7: High

A UV Index reading of 6 to 7 means high risk of harm from unprotected sun exposure. Apply a sunscreen with a SPF of at least 15. Wear a wide-brim hat and sunglasses to protect your eyes.

• Protection against sunburn is needed.
• Reduce time in the sun between 10 a.m. and 4 p.m.
• Cover up, wear a hat and sunglasses, and use sunscreen.

5            8 - 10: Very High

A UV Index reading of 8 to 10 means very high risk of harm from unprotected sun exposure. Minimize sun exposure during midday hours, from 10 a.m. to 4 p.m. Protect yourself by liberally applying a sunscreen with an SPF of at least 15. Wear protective clothing and sunglasses to protect the eyes.

• Take extra precautions. Unprotected skin will be damaged and can burn quickly.
• Minimize sun exposure between 10 a.m. and 4 p.m. Otherwise, seek shade, cover up, wear a hat and sunglasses, and use sunscreen.

6            11+: Extreme

A UV Index reading of 11 or higher means extreme risk of harm from unprotected sun exposure. Try to avoid sun exposure during midday hours, from 10 a.m. to 4 p.m. Apply sunscreen with an SPF of at least 15 liberally every 2 hours.

• Take all precautions. Unprotected skin can burn in minutes. Beachgoers should know that white sand and other bright surfaces reflect UV and will increase UV exposure.
• Try to avoid sun exposure between 10 a.m. and 4 p.m.
• Seek shade, cover up, wear a hat and sunglasses, and use sunscreen.