On the landing page the user can choose the NWP monitoring data type (surface or upper-air observations). Then the control menu allows to select the monitoring category (availability and quality), the date, time, monitoring centre as well as the variable of interest, and a map will display the statistics corresponding to the selection. The tool offers several ways of zooming into the map to view the performance of a particular region or country: either by using the mouse scroll-wheel or by using the zoom buttons on the top right-hand side of the map. Also, the map can be displayed in full-screen mode by using the full-screen toggle button. Another important feature is the possibility of displaying or hiding the legend by using the legend toggle on the top right-hand side of the map. Additionally, it is possible to display on the map only the stations with certain performance levels by clicking onto each performance level (coloured dots) in the legend. Each of these can be switched off and hidden from the displayed map. WDQMS web tool provides a search function that allows to search for stations by name or WIGOS ID on all views. It can be accessed via the magnifying symbol in the top left corner of the map. A Download feature is also available, allowing the user to download a CSV (Comma-Separated Values) file with a summary of the content displayed on the map. This provides a machine readable and exportable representation of the information visible on the map, thus enabling other systems to use the information in WDQMS. The Download feature is accessed in WDQMS maps through the “Download data” link in the bottom right-end corner underneath the map. All CSV files contain the list of stations and the respective NWP monitoring statistics corresponding to the selection (i.e., data type, monitoring category, date, time interval, observed variable and NWP Centre).