We also use data driven maps on TV forecasts now rather than weather symbols such as clouds and suns. But temperature contour maps are nothing new. We started using them in the late 1980s and then ...

BBC weather map row heats up over confusing colours Bright yellow is used for temperatures as low as 11C, while 41C is depicted as dark red ...

Contours. These are lines drawn on maps that join places of the same height. They are usually an orange or brown colour. Some contour lines have their height above or below sea level written on them.