e-RA: the electronic Rothamsted Archive

Meteorological open access data

Open Access Met Data

Selected data from the Rothamsted long term experiments is being made freely available as prepared summaries of commonly requested data. This recognises the national and international importance of the data. The aim is that greater use of the data will lead to further understanding and wider benefits. Rothamsted relies on the integrity of users to ensure that Rothamsted Research receives suitable acknowledgment as being the originators of these data. Please contact the e-RA Curators for help with questions about the data or its interpretation.

We also hope that the Open Access Data will be widely used by schools, colleges and universities, as a teaching resource, and would welcome any feedback on this.

The following Meteorological Open Access Dataset is currently available:

Annual mean Rothamsted temperature

Last updated 21/04/2017

Access Use and Conditions

Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.

YOU MUST CITE AS: Rothamsted Research (2017). Rothamsted mean long-term annual temperature. Electronic Rothamsted Archive https://doi.org/10.23637/KeyRefOARESmatemp.

Click to download chart Annual mean Rothamsted temperature

Click the chart above for a PDF version. Summary data used for this chart are derived from annual daily data measured at Rothamsted Meteorological Station and are available to download as an Excel Spreedsheet: Annual Mean Rothamsted Temperature.

The original raw data is available, after registering, from the e-RA database. Please contact the e-RA Curators for a password and further details.


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 1878-2013. 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.


Daily temperature is measured over the 24 hour period 0900 to 0900 GMT.
Since first recorded in 1878, maximum temperature (TMAX) was measured using a mercury column thermometer and mimimum temperature (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).


Meteorological station
Weather data
Air temperature
Climate change

Further Information

Updated from Scott (2015) see Key Reference below. For further information about the measurement of temperature at Rothamsted see Temperature.
Further details can be obtained from the e-RA curators, the Rothamsted Guide to the Classical Experiments (2006), pp 44-45, and the Key References below.

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Other sources of Open Access Met Data:

The UK Environmental Change Network (ECN) provides many meteorological data variables measured at Rothamsted which can easily be downloaded. There are daily, monthly and annual charts on many variables including maximum and minimum air temperature, soil temperature, rain, radiation and wind speed and direction. These are based on weather variables collected on an hourly basis.

Yearly and monthly weather summaries are provided since 2001. These show:

The departure from the 30 year mean (1981-2010) is also shown for sunshine, maximum and minimum temperatures and rainfall.

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