Not surprisingly, in this ever warming world of ours, the dates of the earliest and latest air frosts in Central England getting respectively later and earlier. The code behind that produced the scatter graphs below was a lot harder than I imagined. Along with the scatter graph and data grid, I also decided to add a smaller horizontal bar chart just to plot the annual distribution. The application is a lot more versatile than just finding the earliest and latest frosts and will come in useful in spotting other events in the daily CETCET Central England Temperature series.
As you can see from the linear trend in the graph below of minimum temperatures, the date of the latest air frostair frost An air frost occurs when the temperature of the air falls below 0.0°C in Central England is now closer to the 5th of April, much earlier than the 16th it was back in 1878.
The date of the first air frost is now 11 days later on the 13th of November, rather than the 2nd of November, as it was closer to back in 1878.