Central England temperature

The Central England Temperature (CET) record was originally published by Professor Gordon Manley in 1953 and subsequently extended and updated in 1974, following many decades of painstaking work. The monthly mean surface air temperatures, for the Midlands region of England, are given (in degrees Celsius) from the year 1659 to the present.

This record represents the longest accurate series of monthly temperature observations in existence. It is an extremely valuable dataset for meteorologists and climate scientists. It is monthly from 1659, and a daily version has been produced from 1772. The monthly means from November 1722 onwards are given to a precision of 0.1°C. The earliest years of the series, from 1659 to October 1722 inclusive, for the most part only have monthly means given to the nearest degree or half a degree, though there is a small 'window' of 0.1 degree precision from 1699 to 1706 inclusive. This reflects the number, accuracy, reliability and geographical spread of the temperature records that were available for the years in question.

The series has useful to researchers of Global Warming because the trends in temperatures since the mid-17th century can be followed. It shows that temperatures fell during the period roughly 1650-1700 and then rose sharply in the early 1700s During the 18th and 19th centuries, a cool period which coincided with the "Dickensian Winters", the temperatures fluctuated widely but with little trend. From 1900, temperatures increased slightly until about 1950 when they flattened before a sharp rising trend began in about 1975. Temperatures so far in the current decade (years 2001-2007) are remarkably different in all seasons from the long-term average.

For recent years there are two versions of the series: the "official" version maintained by the Hadley Centre, and a version maintained by Philip Eden which he argues is more consistent with the series as originally compiled by Manley.