Radcliffe Meteorological Station, Oxford

An observatory with a weather station

The Radcliffe Observatory was built in Oxford in the 1770s with money left by the physician John Radcliffe; Thomas Hornsby, its first observer, began meteorological records in 1772. Records from earlier at Oxford, from 1767, are held in the same collection, and the University's Oxford Weather and Climate since 1767 project covers the whole sequence.

The unbroken daily air temperature series begins in November 1813 and the daily rainfall series in January 1827; sunshine records began in February 1880. In 1934 the Radcliffe Trustees sold the observatory, and the building later became part of Green Templeton College; the station continued in the grounds.

Why this series is trusted

A long weather record is worth only as much as its documentation. The University's team has traced the station's history: its instruments have never moved more than 40 metres from the observatory building, and changes of thermometer, screen and exposure are recorded. The surroundings changed, from fields to a city, and the record shows the effect of urban growth separately from the weather itself.

The same attention to metadata is what makes the series usable in climate research. Researchers can correct for known changes rather than guess at them.

Today

The station is operated by the School of Geography and the Environment at the University of Oxford and still records daily. Its records are part of the United Kingdom's long climate record and put the present climate in a long context.

Why Oxford is a reference

The Oxford record is valued not for its extremes but for its documentation. Researchers know where each instrument stood, what screen sheltered it and when it changed, so the series can be adjusted for known influences rather than guessed at. The record shows the warming of recent decades. It is one of a handful of stations used to check reconstructions of English climate before 1850. Its limitation is the single site: it represents Oxford, not the country, and the growth of the city around it is part of what it shows. A long record should say what it represents.

Instruments and technologies

• Liquid-in-glass thermometers in a screen Maximum and minimum thermometers read daily in a louvred screen; the screen's design and position are part of the metadata.
• Rain gauge A standard gauge at a fixed height, read each morning; the series changed gauge only with overlapping measurements.
• Sunshine recorder A glass sphere that focuses sunlight to burn a trace on a card, giving hours of bright sunshine.

The people

• Thomas Hornsby Savilian Professor and first Radcliffe Observer, who began the records in 1772.

Timeline

• 1772 Meteorological records begin.
• 1813 Unbroken daily air temperature series begins (November).
• 1827 Unbroken daily rainfall series begins (January).
• 1880 Sunshine record begins (February).
• 1934 The Radcliffe Trustees sell the observatory; the building later becomes part of Green Templeton College.

Key lessons for observation today

• Never move the instrument without recording it The station stayed within 40 metres of its start. A modern network keeps a station history of every move, replacement and screen change.
• Overlap before you change A new gauge or thermometer is run beside the old one so the series stays continuous. This is basic practice in any long climate record.
• Metadata makes a record trustworthy The value of a 250-year series is in its documentation. Machine-readable station metadata is what lets it be reused.

Sources

• University of Oxford, School of Geography and the Environment, The Radcliffe Meteorological Station
• University of Oxford, Oxford Weather and Climate since 1767
• Wikipedia, Radcliffe Observatory