Central England temperature

From Wikipedia, the free encyclopedia
Jump to: navigation, search

The Central England Temperature (CET) record is a meteorological dataset 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 series of monthly temperature observations in existence. It is a 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.

Data quality[edit]

Although best efforts have been made by Manley and subsequent researchers to quality control the series, there are data problems in the early years, with some non-instrumental data used. These problems account for the lower precision to which the early monthly means were quoted by Manley. Parker et al. (1992) [1] addressed this by not using data prior to 1772, since their daily series required more accurate data than did the original series of monthly means; MBH98 only used data from 1730 onwards. Before 1722, instrumental records do not overlap and Manley used a non-instrumental series from Utrecht compiled by Labrijn (1945), to make the monthly central England temperature (CET) series complete. Between 1723 and the 1760s most observations were taken not from outside measurements but from indoor readings in unheated rooms, and thus are of little or no use.

Trends revealed by the series[edit]

Annual Mean temperature

During the eighteenth and nineteenth centuries, a cool period which coincided with snowy winters and generally cool summers, the temperatures fluctuated widely but with little trend. From 1910, temperatures increased slightly until about 1950 when they flattened before a sharp rising trend began in about 1975. Temperatures in the most recent decade (years 2001-2010) were slightly higher in all seasons than the long-term average.[2]

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.[3]

Extrema[edit]

Taking the 354-year period for the series as a whole:

Hottest[edit]

Period Record Year
Year 10.82 °C (51.48 °F) 2006 [4]
Spring (March–May) 10.23 °C (50.41 °F) 2011
Summer (June–August) 17.77 °C (63.99 °F) 1976
Autumn (September–November) 12.62 °C (54.72 °F) 2006
Winter (December–February) 6.77 °C (44.19 °F) 1868/1869
January 7.5 °C (45.5 °F) 1916
February 7.9 °C (46.2 °F) 1779
March 9.2 °C (48.6 °F) 1957
April 11.8 °C (53.2 °F) 2011
May 15.1 °C (59.2 °F) 1833
June 18.2 °C (64.8 °F) 1846
July 19.7 °C (67.5 °F) 2006
August 19.2 °C (66.6 °F) 1995
September 16.8 °C (62.2 °F) 2006
October 13.3 °C (55.9 °F) 2001
November 10.1 °C (50.2 °F) 1994
December 8.1 °C (46.6 °F) 1974 and 1934

Coldest[edit]

Period Record Year
Year 6.84 °C (44.31 °F) 1740
Spring (March–May) 5.64 °C (42.15 °F) 1837
Summer (June–August) 13.10 °C (55.58 °F) 1725
Autumn (September–November) 7.49 °C (45.48 °F) 1676
Winter (December–February) −1.17 °C (29.89 °F) 1683/1684
January −3.1 °C (26.4 °F) 1795
February −1.9 °C (28.6 °F) 1947
March 1.0 °C (33.8 °F) 1674
April 4.7 °C (40.5 °F) 1701 and 1837
May 8.5 °C (47.3 °F) 1698
June 11.5 °C (52.7 °F) 1675
July 13.4 °C (56.1 °F) 1816
August 12.9 °C (55.2 °F) 1912
September 10.5 °C (50.9 °F) 1674 and 1807
October 5.3 °C (41.5 °F) 1740
November 2.3 °C (36.1 °F) 1782
December −0.8 °C (30.6 °F) 1890

See also[edit]

Notes[edit]

  1. ^ Parker, D. E., T. P. Legg, and C. K. Folland, 1992: A new daily Central England Temperature Series, 1772-1991. Int J Climatol, 12, 317-342. [1]
  2. ^ CET Data; Mean annual temperature for 2001 to 2010 is 10.22°C compared to warmest decade of 20th century -the 1990s - 10.06°C, and the warmest decade of the period 1659 to 1900 - the 1730s - 9.54°
  3. ^ Checking the CET
  4. ^ 2006 sets British heat records, BBC News, Thursday, 14 December 2006

References[edit]