The scale below shows different
levels on the UV Index:
UV Index of 1 to 2
Minimal sun protection required for
normal activities. Wear sunglasses on sunny days. If you are
outside for more than an hour, cover up and use sunscreen.
UV Index of 3 to 5
Take precautions. Cover up, wear a hat
and sunglasses, and apply sunscreen—especially if you are
outside for 30 minutes or longer. Find the shade around midday
when the sun is at its strongest.
UV Index of 6 to 7
Protection needed. Avoid exposure to the
sun between 10 a.m. and
4 p.m., and take every precaution: seek shade, wear a hat and
sunglasses, and apply sunscreen.
UV Index of 8 to 10
Additional precautions needed. Avoid the
sun between 10 a.m. and
4 p.m., and take every precaution: seek shade, cover up, wear a
hat and sunglasses, and apply sunscreen. Unprotected skin will
be damaged and can burn quickly.
UV Index of 11 or more
Take all precautions. Avoid the sun
10 a.m. and 4 p.m., cover up, wear a hat and sunglasses, and
apply sunscreen. Unprotected skin will be damaged and can burn
in just a few minutes.
The Dangers of UV Exposure
You can sunburn even on a cloudy day!
It is important to know that 60-80% of a
person’s lifetime sun exposure is estimated to occur by age 18 - a good
reason to protect children from the sun!
Concrete, sand, water, and snow reflect 85% of
the sun’s UV rays.
Depletion of Earth’s ozone layer continues to
increase your exposure to UV rays!
When are UV Rays the strongest?
The sun’s radiation is strongest during the summer
months. However, you should protect yourself from early spring right through
the fall. If you must be in the sun, wear clothes that cover your skin,
including hats, sunglasses, long sleeved shirts and pants. Exposure also
depends on other factors:
- Time of Day —
UV is greatest when the sun is at its highest
in the sky.
- Season —
While UV exposure is the greatest in the summer
(May—August) in Canada, it is important to remember that UV rays reach
Earth every day and you should be sun safe year-round—including
wintertime! Snow can reflect 85% to 90% of the sun’s UV rays!
- Cloud cover —
The thicker and darker the clouds, the less UV
- Type of surface —
White surfaces, like snow, reflect the sun rays
back at you.
- Elevation —
The higher the elevation, the greater the UV
- Latitude —
UV is strongest at the equator.
- Exposure Time —
The longer you are out in the sun, the more UV
rays you may receive. Remember, you are exposed whenever you’re out:
picnics, Saturday yard chores, spectator/sports events, and more!
- What you are wearing —
exposed and unprotected skin absorbs more UV.
The UV Index and What it Means
Environment Canada’s UV Index measures the intensity
of the sun’s burning UV rays. The higher the number, the stronger the sun’s
rays. In Canada, the scale measures from 1 to 11, but it can reach up to 14
or higher in the southern United States and the tropics.
The daily UV Index forecast is a prediction of the
maximum UV strength for the day. This peak is usually reached in the early
afternoon. UV Index forecasts are widely available between April and
September. Your sources include local TV and radio stations and the
Environment Canada website.