The coldest night of the year

Figure 1

St Valentines day, the 13/14th of February is the coldest night of the year in Central England, this is based on the lowest mean daily minimum temperature record that started in 1878, the mean for that day is just 0.67°C, with a 40% chance of an air frost, and a 4.3% of an ice day. The lowest mean daily maximum on the other hand occurs around four weeks earlier on the 17th of January with a temperature of 6.1°C (fig 1).