Not What You Meant? There are 16 definitions for CET.

Central England temperature

About 3 pages (769 words)

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.

1 Trends Revealed by the Series
2 Extrema
3 See also
4 References

Trends Revealed by the Series

The series has proved invaluable for researchers of the effects of Global Warming because the trends in temperatures since the mid-17th century can be followed. It shows that temperatures appear to have fallen during the period roughly 1650-1700 and then recovered somewhat in the 1700s and then fluctuated around a mean value for the 18th and 19th centuries up to about 1910. From then on, during the course of the 20th century it rose sharply to unprecedented levels, although it stopped rising in the 1950s and 1960s. Since around 1990, another sharp rising trend has developed. Temperatures so far in the current decade (years 2001-2010) are remarkably different in all seasons from the long-term average. ^[1] 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. [1]

Extrema

Taking the 348 year period for the series as a whole: HOTTEST

The hottest year in the sequence was 2006 with a mean annual temperature 10.82°C, a notable jump on the previous record, a tie between 1990 and 1999 with a mean of 10.63°C^[2]
July 2006 was the hottest month recorded in the CET series (19.7°C).This broke a record set in July 1983 (19.5°C) while the previous record had stood for exactly 200 years (July 1783 with 18.8°C).
September 2006 was the hottest September recorded, and this broke a record that had stood since 1729.
May to September 2006 was the hottest extended summer. The hottest high summer (June, July, August) was in 1976 with a mean of 17.77°C.
Autumn 2006 was the hottest autumn on record.
April 2007 was the hottest ever April breaking a record that had stood since 1865.

COLDEST

The coldest year was 1740 at a mean 6.84 °C, coincidentally almost exactly 4° behind the record hottest.
The coldest ever month was January 1795 with a mean temperature of -3.1°C.
Despite the fact that 6 new hottest recorded months have been set in the last 15 years, 60 years have passed since the last time a coldest month record was broken, the coldest February in 1947 (mean temperature -1.9°C), breaking a record set in 1895.
The coldest winter (December, January, February) was in 1684 with a mean of -1.17°C. The devastating winter centred on January 1963 was the 3rd coldest (mean -0.33°C).
The coldest summer was in 1725 with a mean of 13.10°C.
Four months still have records that were set in the 17th century (March, May, June and September).

Annual Mean temperature

References

^ CET Data; Mean annual temperature for 2001 to 2007 is 10.49°C compared to warmest decade of 20th century, 10.06° and warmest decade of the period 1659 to 1900 -the 1730s- 9.54°
^ 2006 sets British heat records, BBC News, Thursday, 14 December 2006