Radcliffe Meteorological Station

The Radcliffe Meteorological Station is located within the grounds of Green Templeton College, in the shadow of the iconic Radcliffe Observatory.

It possesses the longest-running record of temperature and rainfall data for a single site in Britain, running continuously from 1813. Its records, which date back to 1767, are taken in strict accordance with the UK’s national weather service Met Office standards, and yet double the length of Met Office records themselves, which only date back to 1910.

Radcliffe Meteorological Station records

Records taken by the Radcliffe Met Station in 1775

The Radcliffe Met Station has been an invaluable resource for showing long-term trends in England’s – and the world’s – climate. Because of the long duration of its records, it is helping scientists to show increases in extreme weather events, in particular heavy rainfall, which are likely correlated with global warming.

With its roots in 18th century science, the Radcliffe Met Station is a testament to the value of long-term records, and to the ways in which the astronomical legacy of the Radcliffe Observatory is still relevant for present day services.

The Radcliffe Met Station through time

The construction of the Radcliffe Observatory was the idea of Dr Thomas Hornsby (1733-1810), then the University of Oxford Savilian Professor of Astronomy, who is best known for his astronomical work as Radcliffe Observer (1763-1810).

Hornsby approached the Trustees of Dr John Radcliffe with a request for funds for the erection and equipping of an astronomical observatory.

The Radcliffe Observatory was one of several European observatories, including others at Paris and Greenwich, which were built to promote astronomy and navigation.

As well as astronomical observing, various meteorological observations were made at the Radcliffe Observatory; observations of air temperature and pressure were driven by the practical need to understand astronomical refraction. This is the process by which light waves bend as they pass from the vacuum of space and into the Earth’s atmosphere. Refraction disrupted observations of the positions of celestial bodies, which could be affected by the weather conditions at the point of observation. Consequently, astronomers like Hornsby needed to understand local weather conditions in order to ensure the accuracy of their observations.

Radcliffe Meteorological Station records

The rain gauge at the Radcliffe Met Station

Hornsby made regular meteorological observations at the Radcliffe Met Station from 1776, and continued until his death in 1810. Meteorological observations were subsequently carried on by successive Radcliffe Observers, including Abram Robertson (1751-1826), who was responsible for the first publication of the Radcliffe Met Station records of 1816-1821, and Manuel John Johnson (1805-59), who consolidated and published the existing observations and also introduced self-recording instruments.

In 1872, the Radcliffe Met Station became an official reporting station to the Met Office. At this time, its meteorological work predated any government meteorological service for the country by roughly a century.

Monitoring today’s weather

Despite being over two centuries old, the Radcliffe Met Station plays an active role in modern day climate reporting and research. It provides information about historical weather trends, and also about local variations in weather in the Oxfordshire area. It is maintained by the School of Geography and Environment at the University of Oxford.

The instruments used to collect the data are relatively simple: they include a rain gauge and barometer to collect information about rainfall and pressure. Remarkably, these instruments have changed relatively little since the 18th century, when Hornsby used a 12-inch copper funnel as a rain gauge, and a barometer that is now part of the collection at the Museum of the History of Science in Oxford.

Radcliffe Met Station barometer

The station uses a simple barometer to measure air pressure

In recent years, the Radcliffe Met Station’s records helped to show January 2014 was the wettest January on record for 247 years, and its long-term records demonstrate that such heavy rain was somewhat of an outlier in relation to 20th century records.

These records, which provide a context for the historical and local climate of Southern England, are highly valuable to scientists working to understand the mechanisms and consequences of global warming. Long-running data provides unique evidence that extreme weather events, such as very wet English winters, are becoming increasingly likely in a warming world.

Radcliffe Meteorological Station

The station lies in the shadow of the Radcliffe Observatory

Using the past to see the future

Today, many weather stations exist across the UK. The Radcliffe Met Station is no longer unique in this regard, but still, it continues to inform understandings of the past and future climate. The value of the Radcliffe Met Station lies in its history and continuity: by providing a glimpse into the historical and local climate of Southern England, the station  allows researchers to understand how the earth’s climate is changing in relation to natural and man-made causes.

Only by looking at historical records, which connect modern climate science with past astronomical observation, can scientists begin to understand the causes and consequences of global warming.