418/1 CEEFAX1 Sun 2 Apr CEEFAX.TV
THE SUN INDEX: AN EXPLANATION
The sun index recognises four
categories of skin colour: white skin
that burns easily, white skin that
tans, brown and black skin.
The sun index depends on two factors:
the position of the sun in the sky and
the amounts of cloud cover.
Cloud cover however will greatly
affect the sun index. Thick cloud can
greatly reduce levels but certain
types of thin cloud can magnify the
ultraviolet radiation strength.
Data: BBC Weather Centre/Met Office