1.1 Map

When the web application is started, a map (1) is available that allows the user to select a region for generating a climate diagram. The most common tools are available for this purpose:

• Mouse interaction – scroll wheel: zoom in/out
• +/-: zoom in/out (2)
• Select Base Map (3)
  • ESRI Base Map
  • OpenStreetMap

1.2 Select a Location

The selection of a location is quite easy and is done by clicking on a position in the map. Basically, there are two types of data sets available - raster data (see 1.2.1) and station data (see 1.2.2).

In addition, it is also possible to select a position on the map by entering coordinates into the filter menu. You can find it under the map tile (1). In this case a raster cell at this position is selected.

1.2.1 Raster Data

Once you selected a raster data set and clicked on a location, the corresponding raster cell is shown on the map in blue (1). Within this grid cell the resulting climate diagrams are identical. Another indicator that you are seeing raster instead of station data is the note "Climate Cell" at the top of the information popup (2). This popup also contains information about the name of the place you have selected (3) as well as information about the climate classes according to Köppen-Geiger, the altitude and the selected time period (4). With the button "Create Charts" a diagram is created below the map (5).

1.2.2 Station Data

If you click on one of the brown marked dots on the map, a weather station is selected. Once activated the color will change to blue (1).

You can also see that you have selected a station by the note "Climate Station" in the popup (2). This popup also contains information about the name of the place you have selected (3) as well as information about the climate classes according to Köppen-Geiger, the altitude and the selected time period (4). With the button "Create Charts" a diagram is created below the map (5).

1.3 Filter Options

1.3.1 Data Sets

Overall, four data sets are available for the generation of climate charts.

The weather stations’ data set is part of the Global Historical Climatology Network (GHCN). This data set is automatically selected whenever a user clicks on a station (cf. 1.2.2).

In addition, three different raster data sets can be used to generate climate diagrams. Select one of these data sets before clicking on a location in the map. The selection menu is located beneath the map.

After you have chosen the preferred data set, you can select a location in the map.

You can find more information about the datasets in the menu "Datasets & Software".

1.3.2 Time Period

Climate diagrams are often generated for a period of at least 30 years. The web application ClimateCharts.net offers the possibility to adapt this period according to your own requirements. For this purpose, a slider for adjusting the period (1) is available. The Dark grey area shows the maximum time period in which data (independent of the selected dataset) is available. The maximum available time period for the selected data set (2) is shown in white. The length of this bar can vary depending on the selected data set. The selected time period can be adjusted individually by moving the upper and lower limits (3) of the light grey bar.

Only the data of the selected period is processed and displayed in the climate chart. The "Reset" button is used to set the most recent time period with a length of 30 years (4).

2.1 Walter-Lieth Climate Chart

2.1.1 Structure of the Walter-Lieth Chart

The Walter-Lieth Chart contains a number of components, which will be explained in the following:

1. The location’s name. A gazetteer is used to generate the name (https://www.geonames.org/). Alternatively, you can set a name manually.
2. The location’s coordinates.
3. Elevation of the location. For this information, the gazetteer "Geonames" is used as well.
4. Köppen-Geiger Climate Class. (Markus Kottek, Jürgen Grieser, Christoph Beck, Bruno Rudolf and Franz Rubel. 2006. "World Map of the Köppen-Geiger climate classification updated." Meteorologische Zeitschrift 15 (3): 259–263. https://dx.doi.org/10.1127/0941-2948/2006/0130.)
5. Selected time period
6. Visualization of climate data according to Walter-Lieth (1967)
7. Table of the average monthly values used for temperature and precipitation sums.
8. Mean annual temperature and annual precipitation values
9. Information on the completeness of the data within the selected time period
10. Data source (see 1.3.1)
11. Option to display a bar chart

2.1.2 Understanding the Walter-Lieth Chart

The Walter-Lieth Chart is an easy way to show information about the climatic conditions at a selected location The chart visualizes mean monthly temperatures (1) and mean monthly precipitation sum values (2). The values temperature and precipitation have a ratio of 1:2 up to a value of 100 mm mean monthly precipitation. This ratio changes to 1:10 if precipitation exceeds 100 mm.

The resulting intersections between the temperature and precipitation curves create areas of different classifications (color):

• Yellow: The temperature curve lies above the precipitation curve. Arid or semi-arid conditions prevail.
• Light blue: The precipitation curve lies above the temperature curve. Humid conditions prevail.
• Dark blue: The precipitation curve is clearly above the temperature curve (note change in the scaling of the precipitation axis). These conditions are also called per-humid (monthly precipitation sum > 100 mm).

2.2 Distribution Chart (Boxplot)

2.2.1 Structure of the Distribution Chart

1. The location’s name. A gazetteer is used to generate the name (https://www.geonames.org/). Alternatively, you can set a name manually.
2. The location’s coordinates.
3. Elevation of the location. For this information, the gazetteer "Geonames" is used as well.
4. Köppen-Geiger Climate Class. (Markus Kottek, Jürgen Grieser, Christoph Beck, Bruno Rudolf and Franz Rubel. 2006. "World Map of the Köppen-Geiger climate classification updated." Meteorologische Zeitschrift 15 (3): 259–263. https://dx.doi.org/10.1127/0941-2948/2006/0130.)
5. Selected time period
6. Distribution chart (box plot) for the mean monthly temperatures during the selected period
7. Distribution chart (box plot) for the monthly precipitation sums during the selected period
8. Data source (see 1.3.1)
9. Adjustment of the scaling of the y-axis.
   1. Relative = based on the selected data
   2. Fixed = based on all data sets

2.2.2 Understanding the Distribution Chart

This chart visualizes the monthly distribution of the climate parameters included in the Walter-Lieth Chart using a box plot. This kind of chart visualizes the distribution of different parameters. Here, the average sums of monthly temperature and precipitation values are shown. The box plot include:

• Median (middle value of the data set)
• First quartile (25^th Percentile, Q1)
• Third Quartile (75^th Percentile, Q2)
• Interquartile Range (IQR, 25^th to the 75^th percentile; Box)
• Whiskers (Q1 - 1.5*IQR and Q3 + 1.5*IQR)
• Outliers (dots)

image source

Reading boxplots requires some experience and knowledge of data distribution. For more detailed information we recommend the article "Understanding Boxplots" by Michael Galarnyk: https://towardsdatascience.com/understanding-boxplots-5e2df7bcbd51

2.3 Availabilty Chart

2.3.1 Structure of the Availability Chart

The Availability Chart is a detailed tabular representation of the data of the Walter Lieth Climate Chart.

1. The location’s name. A gazetteer is used to generate the name (https://www.geonames.org/). Alternatively, you can set a name manually.
2. The location’s coordinates.
3. Elevation of the location. For this information, the gazetteer "Geonames" is used as well.
4. Köppen-Geiger Climate Class. (Markus Kottek, Jürgen Grieser, Christoph Beck, Bruno Rudolf and Franz Rubel. 2006. "World Map of the Köppen-Geiger climate classification updated." Meteorologische Zeitschrift 15 (3): 259–263. https://dx.doi.org/10.1127/0941-2948/2006/0130.)
5. Selected time period
6. Visualization of the mean monthly temperature values and the monthly precipitation sums involved in the climate diagram.
7. Color-coded scales for temperature and precipitation.
8. Data source (see 1.3.1)
9. Adjustment of the color-coded scales.
   1. Relative = based on the selected data
   2. Fixed =
      1. Temperature: < 5°C to > 35°C
      2. Precipitation: < 40 mm to > 200 mm

2.3.2 Understanding the Availability Chart

The Availability Chart is an easy-to-understand instrument for displaying temperature and precipitation data as numerical values. The color-coding of the table cells allows you to quickly perceive the values. It allows the comparison of the monthly values over the selected time period. It is also possible to identify data gaps. These data gaps occur exclusively in the data set of the GHCN Weather Stations (see 1.3.1).