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Hadley Centre Central England Temperature (HadCET) dataset

The CET dataset is the longest instrumental record of temperature in the world. The mean, minimum and maximum datasets are updated monthly, with data for a month usually available by the 3rd of the next month. A provisional CET value for the current month is calculated on a daily basis. The mean daily data series begins in 1772 and the mean monthly data in 1659. Mean maximum and minimum daily and monthly data are also available, beginning in 1878.

Brief description of the data

These daily and monthly temperatures are representative of a roughly triangular area of the United Kingdom enclosed by Lancashire, London and Bristol. The monthly series, which begins in 1659, is the longest available instrumental record of temperature in the world. The daily mean-temperature series begins in 1772. Manley (1953, 1974) compiled most of the monthly series, covering 1659 to 1973. These data were updated to 1991 by Parker et al (1992), who also calculated the daily series. Both series are now kept up to date by the Climate Data Monitoring section of the Hadley Centre, Met Office. Since 1974 the data have been adjusted to allow for urban warming: currently a correction of -0.2 °C is applied to mean temperatures.

Current Version:

The current version of the CET data series is v2.1.0.0 released July 2024. Information on each new release of the series can be found in the Release Notes section.

New CET Version Release: V2.1.0.0

A new version of the CET dataset has been released and is now available for download on the Download Data page.

All diagnostics plots and tables have been updated to reference the new CET dataset series.

Further information on the changes made to CET can be found in the Release Notes section.

Annual Mean CET — **Figure:** Mean temperature anomalies for each full year in the CET series against 1961-1990 climatology

Data are available from the download page without charge, but please read the terms and conditions.
CET datasets are freely available for use under Open Government License. However, please acknowledge the source if the data are used in any report or product.

Release Notes

Documentation relating to releases of the CET data series can be found by clicking on the link below.

Any updates which result in changes to the methodology or calculation of the series will be documented in the relevant release notes report.

CET Release Notes

CET Annual Release Cycle

Commercial and media enquiries

You can access the Met Office Customer Centre, any time of the day or night by phone, fax or e-mail. Trained staff will help you find the information or products that are right for you.
Contact the Met Office Customer Centre

References

When using the data set in a paper, the correct citation to use for HadCET is:

Parker, D.E., T.P. Legg, and C.K. Folland. 1992. A new daily Central England Temperature Series, 1772-1991. Int. J. Clim., Vol 12, pp 317-342 (PDF)

Other relevant references include:

Manley,G. 1953. The mean temperature of Central England, 1698 to 1952. Q.J.R. Meteorol. Soc., Vol 79, pp 242-261.
Manley,G. 1974. Central England Temperatures: monthly means 1659 to 1973. Q.J.R. Meteorol. Soc., Vol 100, pp 389-405.
Parker, D.E. and Horton, E.B. 2005. Uncertainties in the Central England Temperature series since 1878 and some changes to the maximum and minimum series. International J.Climatology, Vol 25, pp 1173-1188. (PDF)

Other information

The graph above shows annual anomalies relative to the 1961-1990 average. The red line is a 21-point binomial filter, which is roughly equivalent to a 10-year running mean.
HadCET diagnostics for the current year and previous few years.
2006 was the warmest year on record for min HadCET. 2022 was the warmest year on record for mean HadCET. 2022 was the warmest year on record for max HadCET.
HadCET is produced using an operational system which relies on a number of components. Daily support is not available for this system, therefore the data may occasionally not be fully up-to-date. If you encounter any problems or want to request a more reliable service please contact us.