The UK Met Office is presenting an award to the University in recognition of 200 years of continuous Radcliffe climate observations — a record vital for gauging long-term climate change.

Award for 200 unbroken years of Oxford weather records

By Maria Coyle

Oxford University is today being handed a Met Office award to mark two centuries of uninterrupted daily weather records at the Radcliffe Observatory.

The Radcliffe Meteorological Station, based at Green Templeton College and maintained by the University’s School of Geography and the Environment, holds the longest series of temperature and rainfall records for one site in Britain, with daily full records from 1815, and less frequent observations dating as far back as 1767.

Richard Washington, Professor of Climate Science, expressed the University’s delight at the award and added: ‘It provides a moment to pause and remember those with the foresight to embark on extraordinary efforts to record the weather each day so long ago — long before the justification of climate change was to hand.

‘Ours is an old planet, yet one with a very young observational record. But without those 200 years of data, nature, and the way we are influencing it, would be so much harder to understand.’

UK weather stations report a mixture of snapshot hourly observations of the weather, and daily summaries of the weather known as climate observations. Though Radcliffe weather observations are insufficient for short-range weather forecasting, they provide valuable long-term data for climate research. Changing weather patterns in Oxford can be tracked by comparing recent data with the long-term averages.

The combined winter rainfall total for December 2013 to February 2014 was a record-breaker — the wettest winter quarter since full records began in 1815. January 2014 was the wettest of all winter months with rainfall of 146.9mm (5.78in) which, although below the national figure, was nearly three times the month’s long-term average in Oxford of 52.9mm (2.08in).

Award for 200 unbroken years of Oxford weather records

Last year was also Oxford’s warmest since 1815, part of a very warm trend since 1990, with September 2014 being the second driest on record. The average annual temperature for 2014 was 11.5C (52.7F), 1.8 degrees Celsius (3.2 Fahrenheit) higher than the 200-year average of 9.7C (49.5F), a significant difference in weather terms.

The weather station is located in the grounds a few metres away from the Radcliffe Observatory. From the School of Geography and the Environment, doctoral students (including Callum Munday and Amy Creese, pictured bottom) and others (such as postdoctoral researcher Ian Ashpole, pictured top in February 2014 during the wettest winter on record) visit the station once a day, every day, to read the thermometers, check the rain gauge and estimate cloud cover. They also check the atmospheric pressure on a barometer inside the Observatory, and note the sunshine, wind-speed and visibility from the top of the Department of Engineering Science. Since 1925, eye observations have taken place every morning at 09:00 GMT.

Observations were originally made at the Observatory itself, which was set up at the behest of Dr Thomas Hornsby, Savilian Professor of Astronomy at Oxford, after he requested funds in 1768 for an astronomical observatory from the Radcliffe Trustees at a cost of £30,000.

Award for 200 unbroken years of Oxford weather records

As the first Radcliffe Observer, Dr Hornsby erected a rain gauge, thermometers, and wind-speed recorder on the flat roof of the small rectangular room he had established for astronomical observations on the top of the Tower. His weather records were compiled in order to correct star observations, but became increasingly important in their own right.

Hornsby’s surviving meteorological records include fragments of a weather journal with entries for various dates between 1760 and 1804. On 27 January 1776, it was so cold he read the temperature 12 times instead of the usual three, noting in his journal that ‘this day wine keg in my study froze’. The lowest air temperature he recorded in Oxford that day was about 6°F, which is just below -14°C. Some of the instruments he used are preserved in the Oxford Museum of the History of Science.

Today Professor Washington is accepting a commemorative shield on behalf of Oxford from Met Office regional network manager Phil Johnson, during a visit by members of the Royal Meteorological Society as part of the bicentennial celebrations.

Award for 200 unbroken years of Oxford weather records

Mr Johnson said: ‘Weather observation sites are crucial to the way that we observe and record the climate around the UK. Our climate analyses would not be possible without the long-running, high-quality individual station series such as the Radcliffe Observatory.

‘These observations are used in a variety of different ways, including supporting automated observations, making historical records and contributing to climate change calculations. We rely on skilled observers at sites such as Oxford to provide us with accurate data.’

Images © Ian Curtis, reproduced by kind permission.


By Peter Hulse

"Radcliffe weather observations are insufficient for short-range weather forecasting". Why have the observations not been modified in accordance with the latest requirements?