Central England has weather data going back a long time. 1772 for daily average temperature and 1878 for maximum and minimum temperatures on each day.
2 times February the 25th since 1772 had an average temperature for the day above 10°C in Central England 1790 with 10.7°C, and 1922 with 11°C
The maximum temperatures observed in central England on the 25th of February were 1922 with 14.1,1953 with 13.1 and 1976 with 13.1 For those 140 years the maximum daily temperature averaged 6.6C.
I put the code to work all this out here. Graph of Feb 25th max temperature shows how weird 20°C is
It takes a while for the HADCET data to be updated. There is a nearby weatherstation http://www.weathercast.co.uk/world-weather/weather-stations/obsid/99060.html when I figure out the relationship between the two it will be possible to do a comparison between today and all the previous years.