Since August 2019, users of the RMI smartphone app are able to send an observation of the meteorological conditions at a certain place and a certain time. The observations provide information about the weather conditions and potentially severe weather to the other users and to RMI. The collection of citizen weather reports is a valuable complement to the information obtained with the classical instruments like stations, radar and satellite. The data can be exploited for nowcasting, warnings and model verification, and eventually in assimilation. A general introduction of the data and their characteristics can be found in Reyniers et al. (2023). A basic quality control is implemented on the received observations via a plausibility check. This plausibility check determines whether an observation is plausible, suspicious or false, by comparing it to the INCA-BE nowcasting system using a simple thresholding scheme. INCA-BE is RMI's operational nowcasting system described in Reyniers et al. (2021). There is no strict spatial extent since there is no restriction at the input side: users can send observations from all over the globe. The bulk of the observations are received from within Belgium. Note that the plausibility check is not available for reports from outside Belgium.

From multiple observations during the day with UV spectrophotometers a daily value of the ozone column is calculated. This product is not publically available yet.

The air quality monitoring networks in Belgium are used for the assessment of air quality under the air quality directives (2008/50/EC & 2004/107/EC).

Hail products are derived from the observed vertical profiles of radar reflectivity and the NWP vertical profiles of temperature. Three types of products are generated. poh : probability of hail of any size (larger than 0.5 cm diameter)expressed in %. posh : probability of severe hail(larger than 2cm)expressed in %. mesh : maximum expected size of hailexpressed in mm of hailstone diameter. All products are generated every 5 minutes. This product is not publically available yet.

RADCLIM is a historical dataset based on weather radar observations that provides gridded accumulated precipitation composites over Belgium and surrounding regions. The data are distributed in ODIM_H5 version 2.2 format. The reported quantity is accumulated precipitation (ACRR) for 5-minute and 1-hour accumulation periods. UTC is used as the time reference, and the timestamp in the filename corresponds to the end of the accumulation period. The dataset is produced on a 700 × 700 grid with 1 km spatial resolution in the Belgian Lambert 2008 projection (Lambert Conformal Conic).

The data set has been established according to the INSPIRE format. It presents in the form of polygons the breakdown of Belgium in almost 20,000 statistical sectors. The statistical sector is the basic territorial unit resulting from the subdivision of the territory of municipalities by STATBEL since 1970 for the dissemination of its statistics at a finer level than the municipal level. A statistical sector cannot extend over two municipalities and any point in the municipal territory is part of one and the same statistical sector. The 1970 and 1981 versions are shown in analogue format while the 2001, 2011, 2018, 2019 etc. versions are available in digital vector format. The files can be linked to the data on population, housing and disposable income on the website of Statbel.

Share of the cadastral surface area that is not artificially developed in the cadastral and not unknown surface area to the administrative entity (region, province, district and municipality) for Wallonia

This dataset consists of historical aerial imagery (1947-2007) commissioned by the National Geographic Institute. It includes the spatial footprints and metadata of individual photographs as well as the corresponding flight paths of the aircraft used during image acquisition.

The ceilometer CL51 employs a pulsed diode laser LIDAR technology, where short, powerful laser pulses are sent out in a vertical or near-vertical direction. The reflection of light (backscatter) caused by clouds, precipitation or other obscuration is analysed and used to determine the cloud base height, the cloud layer height and the amount of clouds (in octas) in different layers.

Gridded observational data provides an estimate of the spatial distribution of a meteorological variable based on observations. While instrumental measurements are taken at irregularly distributed stations, gridded data represents the meteorological variable on a predefined regular grid. Gridded observational data is of strong benefit in disciplines applying distributed quantitative models to examine the influence of weather and climate. Gridded data are also very convenient to provide estimations for any specific location of interest for the user. Gridded observational data covering Belgium at a spatial resolution of 5 km (= 1360 pixels) are available for several variables (precipitations, air temperature, sunshine duration, solar radiation, relative humidity and wind speed) as well as different temporal resolutions (daily, monthly, seasonal, annual values as well as long-term climate averages). The gridded database starts in 1961 for most variables and is updated each day with the available observations of the previous day. All grids are then updated for archiving as soon as the data quality control is completed. In addition to the 5km x 5km grids, spatial averages for all each Belgian municipality are also available. This product is not publically available yet. The daily gridded climate data are available for academic profiles after registration on our open data website.