A climate diagram is a graphic representation of the form of climatic conditions in a particular place during the year.

Conclusion of the measured values

In the most frequently used hygrothermal ( gr hygrostat = water, moisture and gr thermos = hot, heat) climate diagrams are taken into account measured values ​​for precipitation ( N ) and temperature ( T). These are represented as a 30- year mean values ​​corresponding to the climate normal periods (Definition air = period of 30 years ). This means that the (usually to the Mannheim hours 7 clock, 14 clock and 21 clock ) measured over a period of 30 years, values ​​for T and N are averaged for each month (the values ​​for N are not averaged, but accumulated ), and this average value is listed in the climate chart.

The benefits of a climate chart

The climate diagram provides the opportunity to make a quick, rough estimate of the local weather conditions already brief consideration. So any aridity and / or Humidität can be determined in hygrothermal charts, which in turn suggests drought and vegetation conditions, and thus, for example, determines the potential for human land use.

Types of climate diagrams

One can find various types of climate diagrams differ: Walter / Lieth climate diagram Thermoisoplethendiagramm, Klimogramme and diagrams easily deviate from the conventions of these types.

Walter / Lieth climate diagram ( hygrothermal )

In type by Heinrich Walter and Helmut Lieth frequently used is traditionally the average monthly temperature (T) the average monthly precipitation ( N) during the year compared ( = hygrothermally ). It is understood from a function of the evaporation of the air temperature.

The representation of the values ​​is carried out for the temperature by a red curve, and the precipitates either by means of a blue column or a blue curve. [ Note 1 ] T is in ° C and N in mm (equivalent liters per square meter). Runs the precipitation curve above the temperature curve, it is called Humidität, in the opposite case of aridity. Intersect the curves, there is a changeable climate, as it occurs in the interior of continents ( continentality ).

The standards for the units of T and N are in the ratio 1:2 ( ie 10 ° C are listed at the same height as the y-axis 20 mm N). From 100 mm rainfall N is shown 5 times too high in general (one step on the y- axis corresponds to 100 mm N instead of the previous 20 mm N). This cant be seen at climate diagrams of places (at times) are very humid (eg when getting wet, tropical climates or seasonally wet Monsunklimaten, see below). Due to the 1:2 ratio immediately statements on Humidität or aridity can be made when looking at the chart, since humid months are defined so that their potential evaporation is exceeded by the rainfall (ie, that generally water for plant remains ). Aridity is sometimes illustrated by the exceeding of the temperature curve is highlighted in color, so the integral between T and N ( if no precipitates are present, the integral under the T curve, as shown below in yellow).

Thermoisoplethendiagramm (thermal)

The Thermoisoplethendiagramm (Greek thermos = heat; isopleth = lines of equal values ​​) is based only on the averaged temperature values ​​of a place. Here, although no precipitation are represented, but also the daily variation of temperature is shown among other things in addition to the course of the year. Thus, a classification in the year or day time air is possible.

Note: In addition Thermoisoplethen there is another type of lines of equal temperature: the isotherms. As isotherms, however, only the lines in PV diagrams or weather maps are called, therefore deviating name Thermoisoplethe.


Other forms of presenting climatic conditions, for example, a part of the Klimogramm showing the ratio of T to N by a function curve graphically.

Some climate diagrams take into account the ratio of monthly temperature maximum to minimum temperature and demonstrate this by vertical bars for each month is (see also box plot ). The upper value of this bar (often at temperature daily values ​​because sunshine can increase T ) corresponds to the average measured monthly maximum. The lower limit of the bar represents the average measured minimum ( often night values). In part, the temperature values ​​are given in the diagram.


Walter / Lieth climate diagram of a tropical climate

Walter / Lieth climate diagram of a maritime climate

Walter / Lieth climate diagram of a humid continental climate

Walter / Lieth climate diagram of an embossed by the monsoon climate

Thermoisoplethen diagram ( based only on temperature, but this is full of day - to represent the course of the year )

Beam - columns Klimogramm ( average boxplot )

Walter / Lieth climate diagram of a summer humid tropics climate ( monsoon influence), with precipitation bar (seasonal excessive ) and temperature curve

Air table

An air table is an alternative graphical representation of the climate at a particular location. Example: Hechingen.