Climate of The United Kingdom - Rainfall

Rainfall

Rainfall amounts can vary greatly across the United Kingdom and generally the further west and the higher the elevation, the greater the rainfall. The mountains of Wales, Scotland, the Pennines in Northern England and the moors of South West England are the wettest parts of the country, and in some of these places as much as 4,577 millimetres (180.2 in) of rain can fall annually, making these locations some of the wettest in Europe. The wettest spot in the United Kingdom is Crib Goch, in Snowdonia, which has averaged 4,473 millimetres (176.1 in) rain a year over the past 30 years. Most rainfall in the United Kingdom comes from North Atlantic depressions which roll into the country throughout the year from the west or southwest and are particularly frequent and intense in the autumn and winter. They can on occasions bring prolonged periods of heavy rain, and flooding is quite common.

Parts of England are surprisingly dry, which is contrary to the stereotypical view—London receives just below 650 millimetres (25.6 in) per annum, which is less than Rome, Sydney or New York City. In East Anglia it typically rains on about 113 days per year. Most of the south, south-east and East Anglia receive less than 700 millimetres (27.6 in) of rain per year. The English counties of Essex, Cambridgeshire - as well as parts of North Yorkshire, the East Riding of Yorkshire, Suffolk and Norfolk - are amongst the driest in the UK, with an average annual rainfall of around 600 millimetres (23.6 in). This is due to a mild rainshadow effect, due to mountainous parts of the South West, Wales and Cumbria blocking the moist airflow across the country to the east. In some years rainfall totals in Essex and South Suffolk can be below 450 millimetres (17.7 in) (especially areas around Colchester, Clacton and Ipswich) - less than the average annual rainfall in Jerusalem, Beirut and even some semi-arid parts of the world.

Parts of the United Kingdom have had drought problems in recent years, particularly in 2004-2006. Fires broke out in some areas, even across the normally damp higher ground of north-west England and Wales. The landscape in much of England and east Wales became very parched, even near the coast; water restrictions were in place in some areas.

July 2006 was the hottest month on record for the United Kingdom and much of Europe, however England has had warmer spells of 31 days which did not coincide with a calendar month—in 1976 and 1995. As well as low rainfall, drought problems were made worse by the fact that the driest parts of England also have the highest population density, and therefore highest water consumption. The drought problems ended in the period from October 2006 to January 2007, which had well above average rainfall.