Ultraviolet index. The ultraviolet index or UV Index is an international standard measurement of the strength of sunburn-producing ultraviolet (UV) radiation at a particular place and time. The scale was developed by Canadian scientists in 1992, then adopted and standardized by the UN's World Health Organization and World Meteorological Organization in 1994.
one-quarter-one of four equal parts; a quarter of a pound. fourth part, one-fourth, quarter, quartern, twenty-five percent, fourth. common fraction, simple fraction-the quotient of two integers.
But first quarter refers not to the Moon's appearance, but to its position in its month-long cycle of phases. And today, it's one-quarter of the way through that cycle. It'll be half-way through the cycle on the 17th.