This one supposedly originates from the bible, but can the colour of the sunset really be used to predict the weather? The meaning of the phrase is that a red sky at sunset means that the weather will be fair and dry the next day and, according to the Met Office, the science stands up. Generally speaking, weather systems will travel from west to east, so incoming weather can be seen to the west - the same direction that the sun happens to set. A vibrantly red sunset is caused by the sun's rays being scattered through particles in the atmosphere. The more particles there are, the more the light will scatter and the redder it will appear. High levels of dust, dirt and or junk in the air is an indicator of a high pressure system moving in, and so the next day is likely to be pleasant and dry. Alternatively, a red sky in the morning (shepherd's warning) will indicate that the high pressure system has already moved past and is probably dragging an area of wet and windy low pressure behind it.
