Llysdinam Gardens’ long history as an observing station was recognised this week with the unveiling of a plaque by BBC Wales weather presenter Sue Charles.

The Newbridge-on-Wye-based site, part of the Met Office’s climate network, joins a global network of stations that have been recognised by the World Meteorological Organisation for recording weather for more than 100 years. Sir Charles Venables Llewelyn was the first to collect weather data there, keeping records of maximum/minimum temperature from the 1880s.

The Llewelyn family continued collecting meteorological data until the 1970s when Cardiff University took over. In 1988 Llysdinam was upgraded to a climatological site, with soil temperatures, wet and dry bulbs and climatic descriptions sent monthly to the Met Office.

In 2010 Llysdinam recorded the coldest November day in the UK, -18°C. It was the year the site went automatic with its data transported to the Met Office electronically.

Adam Barber, the Met Office’s climate network manager, said: “Without the individuals who, over the years, have cared for this site and submitted daily observations, the irreplaceable record of the UK’s climate would not have survived.”

The weather station is situated at the heart of Llysdinam Gardens, which is run by the Llysdinam Charitable Trust. The six-acre gardens are especially noted for a magnificent display of rhododendrons and azaleas at this time of year.