An isohyet or isohyetal line on a map connects two points having the same what?
Contour line isotherms in Paris, in 1817. An isogeotherm is a line of equal mean annual temperature. An isocheim is a line of equal mean winter temperature, and an isothere is a line of equal mean summer temperature. An isohel (from or "helios", meaning 'Sun') is a line of equal or constant solar radiation. An isohyet or isohyetal line (from or "huetos", meaning 'rain') is a line joining points of equal rainfall on a map in a given period . A map with isohyets is called an isohyetal map. An isohume is a line of constant relative humidity, while a isodrosotherm (from
Contour line height on a constant pressure surface chart. Isohypse and isoheight are simply known as lines showing equal pressure on a map. An isotherm (from or "thermē", meaning 'heat') is a line that connects points on a map that have the same temperature. Therefore, all points through which an isotherm passes have the same or equal temperatures at the time indicated. An isotherm at 0 °C is called the freezing level. The term was coined by the Prussian geographer and naturalist Alexander von Humboldt, who as part of his research into the geographical distribution of plants published the first map of