Wettest April since 1767 according to longest rainfall dataset

'We can show that this was in fact the wettest for almost 250 years and not just 100 years as previously reported. However, the mean air temperature in Oxford for April was 8.1 degrees Celsius (measured at 0900UCT) with the long-term mean being 8.3 degrees Celsius. This is very much in line with expected mean temperatures for this time of year.'

Oxford wasn't quite as wet as the average for Wales or southwest England, which means that within those areas there will have been places receiving much more rain than Oxford, according to this data collection.

Richard Washington, Professor of Climate Science at Oxford University, said: 'The floods may have been worse if the rain had fallen earlier in the spring or winter when the evaporation rates are lower. But it is also likely that the weather systems might not have produced as much rain then either, as that is when the air temperatures and the moisture content of the air are generally lower too.'

The Radcliffe Meteorological Station has collected the longest series of temperature and rainfall records for one site in Britain. These records are continuous from January, 1815. Irregular observations of rainfall, cloud and temperature exist from 1767.

Observations of air temperature were taken at observatories to determine astronomical refraction, but other meteorological observations were often made. The building of the Radcliffe Met Station began in 1772 when Thomas Hornsby, then Savilian Professor of Astronomy, approached the Radcliffe Trustees with a request for funds for the erection and equipping of an astronomical observatory.

Hornsby might have had some personal interest in weather for he made numerous but irregular observations from 1767 until his death in 1810. Daily readings were first published from 1853 onwards.