How to read the map:
Warm days are defined as being above the 90th percentile of the daily maximum temperature.
Grid boxes outlined in solid black contain at least 3 stations and so are likely to be more representative of the grid-box. Higher confidence in the long-term trend is shown by a black dot. Area averaged annual time series of percentage changes and trend lines are shown below each map for one area in northern Europe (Green line, 5.6 to 16.9 E and 56.2 to 66.2 N) and one in south-western Europe (Pink line, 350.6 to 1.9 E and 36.2 to 43.7 N).