Power systems: Weak power grid fluctuations can occur.
Spacecraft operations: Minor impact on satellite operations possible.
Other systems: Migratory animals are affected at this and higher levels;
aurora is commonly visible at high latitudes (northern Michigan and Maine).
On land:
Thin branches and tree trunks sway, and the wind is felt by the hand.
At Sea:
The sea is rough, not very large waves are well developed in length; many white horses are formed.
Enhanced protection from UV radiation from the Sun is required. A UV index reading of 11 or more means extreme risk of harm from unprotected sun
exposure. Take all precautions because unprotected skin and eyes can burn in minutes.
Try to avoid sun exposure between 10 a.m. and 4 p.m. If outdoors, seek shade and wear sun
protective clothing, a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad
spectrum SPF 30+ sunscreen every 2 hours, even on cloudy days, and after swimming or sweating.
Bright surfaces, such as sand, water, and snow, will increase UV exposure.
On land:
The wind picks up dust and small pieces of paper; small branches are moved.
At Sea:
The sea is moderately rough. Waves appear in the form of elongated ridges, some of which are overturned; fairly frequent white horses.
Enhanced protection from UV radiation from the Sun is required. A UV index reading of 8 to 10 means very high risk of harm from unprotected sun exposure.
Take extra precautions because unprotected skin and eyes will be damaged and can burn quickly.
Minimize sun exposure between 10 a.m. and 4 p.m. If outdoors, seek shade and wear sun protective clothing,
a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen
every 2 hours, even on cloudy days, and after swimming or sweating.
Bright surfaces, such as sand, water, and snow, will increase UV exposure.
On land:
The thin branches and leaves on the trees fluctuate continuously; wind extends light flag.
At Sea:
Light and short waves are clearly visible at sea. Foam of glassy appearance. Perhaps scattered white horses.
Protection from UV radiation from the Sun is necessary. A UV index reading of 6 to 7 means high risk of harm from unprotected sun exposure.
Protection against skin and eye damage is needed.
Reduce time in the sun between 10 a.m. and 4 p.m. If outdoors,
seek shade and wear sun protective clothing, a wide-brimmed hat, and UV-blocking sunglasses.
Generously apply broad spectrum SPF 30+ sunscreen every 2 hours,
even on cloudy days, and after swimming or sweating. Bright surfaces, such as sand, water, and snow,
will increase UV exposure.
Protection from UV radiation from the Sun is necessary. A UV index reading of 3 to 5 means moderate risk of harm from unprotected sun exposure.
Stay in shade near midday when the sun is strongest. If outdoors, wear sun protective clothing,
a wide-brimmed hat, and UV-blocking sunglasses. Generously apply broad spectrum SPF 30+ sunscreen
every 2 hours, even on cloudy days, and after swimming or sweating. Bright surfaces, such as sand,
water, and snow, will increase UV exposure.
Protection from UV radiation from the Sun is not necessary. A UV index reading of 0 to 2 means low danger from the sun's UV rays for the
average person.
Wear sunglasses on bright days. If you burn easily, cover up and use broad spectrum SPF 30+ sunscreen.
Bright surfaces, such as sand, water, and snow, will increase UV exposure.
On land:
There is a light continuous stream of wind that is felt by the face; leaves rustle; ordinary vanes moved by wind.
At Sea:
Weak and short waves in the sea, still short, but more pronounced. Crests have a glassy appearance and do not break.
On land:
Direction of wind shown by smoke drift, but not by wind vanes.
At Sea:
There are very weak waves at sea. Ripples with the appearance of scales are formed, but without foam crests.
Marintoumania +43 °C 
Sero +44 °C 
Sandare +42 °C