Dataset: Annual Mean Air Temperature at Rothamsted 1878-2019

Annual Mean Rothamsted Temperature 1878-2019 (figure)

Annual Mean Rothamsted Temperature 1878-2019 (figure)


Rothamsted has one of the longest running continuous sets of meteorological recordings in the world. The figure shows the annual mean air temperature at Rothamsted every year from 1878-2019. Also shown is the mean over each five-year period, 1878-1882, 1883-1887, etc. The red line shows the mean temperature, 1878-1987. Mean annual air temperature has fluctuated considerably between 1878-2013. However, when the variation in annual temperature is smoothed using five-year means, it is apparent that air temperatures have risen sharply since 1987 (Scott, 2015). The mean air temperature at Rothamsted is now approximately 10.04°C which is 1.1°C higher than the 1878-1987 average. The 10 warmest years on record occurred in the last 17 years. Much of the rise is due to increases in the autumn and winter months, and in night time temperatures.


Summary data used for this chart are derived from annual daily data measured at Rothamsted Meteorological Station. The mean daily temperature is measured over a 24 hour period 0900 to 0900 GMT and calculated from the daily maximum (Tmax) and minimum temperatures (Tmin); the mean daily tamperature = (Tmax = Tmin)/2.

Technical Information

First recorded in 1878, Tmax was then measured using a mercury column thermometer and Tmin using a spirit-in-glass with indicator bar minimum thermometer.

Since 2004, temperatures have been recorded automatically by thermistors (electronic temperature probes, Campbell Scientific, Type 107).

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Previous Versions


  • Sarah Perryman: Data curator
  • Tony Scott: Data collector
  • Chris Hall: Data collector
  • Margaret Glendining: Data curator
  • Nathalie Castells-Brooke: Data manager
  • Richard Ostler: Project leader
  • Andrew Macdonald: Project manager

Dataset Access and Conditions

Rights Holder

Rothamsted Research


Creative Commons License This dataset is available under a Creative Commons Attribution Licence (4.0).

Cite this Dataset

YOU MUST CITE AS: Sarah Perryman, Tony Scott, Chris Hall (2020). Dataset: Annual Mean Air Temperature at Rothamsted 1878-2019 Electronic Rothamsted Archive, Rothamsted Research 10.23637/rms-RMAAtemp-02

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For further information and assistance, please contact the e-RA curators, Sarah Perryman and Margaret Glendining using the e-RA email address: