miniature sheet from the German Democratic Republic is based on a
manuscript map drawn by Waldimer Köppen in 1876 which has lines
showing wind speed.
design of the Meteorological Readings postage stamp incorporates an
authenticated section of a recent surface weather map prepared by the
Meteorological Branch of the Canadian Department of Transport."
Canada Post Office
Postage Stamp Press Release, 1968
contours on the map indicate barometric pressure. H and T indicate
"Highs" and "Lows." The symbols in the weather map below indicate the
nature of the weather in the area. The blue points indicate cold
fronts; red half circles, warm fronts; triangles, showers; circles
with a line, wind coming from the direction of the line to the circle;
one bar at the top of the line,8-12 knot wind; the amount of black in
the small circle, the amount of cloud cover.