Warmest May night since 1953 

Coulsdon recorded its warmest May night since 1953 with 15.5C on the night of the 23rd/24th 2012. A combination of humid air, haze, still quite high moisture levels in the ground and then low cloud sealing in the heat from the day meant that the temperature remained high. The previous Sunday (20th) the maximum temperature was only 12.5C.
In May 1922 on the night of the 21st/22nd May the temperature did not fall below 18.3C at nearby Addington. This was probably the highest minimum value in Surrey and London on record for May.