Monthly homogenized temperature and precipitation series for Belgium (NOISELESS)

The monthly homogenized temperature and precipitation series for Belgium are available for different variables and at different time periods:

  • 16 extreme minimum temperature (TN) series, 1880-2024
  • 15 extreme maximum temperature (TX) series, 1880-2024
  • 24 precipitation (RR) series, 1880-2024
  • 60 extreme minimum temperature (TN) series, 1954-2024
  • 60 extreme maximum temperature (TX) series, 1954-2024
  • 158 precipitation (RR) series, 1951-2024

The monthly regional temperature and precipitation series developed from the homogenized series are available as:

  • 1 national extreme minimum temperature (TN) series, 1954-2024
  • 1 national extreme maximum temperature (TX) series, 1954-2024
  • 1 national precipitation (RR) series, 1951-2024
  • 3 sub-regional extreme minimum temperature (TN) series, 1954-2024
  • 3 sub-regional extreme maximum temperature (TX) series, 1954-2024
  • 3 sub-regional precipitation (RR) series, 1951-2024

To construct monthly series, daily observations were first aggregated into monthly statistics: means for temperature variables and sums for precipitation. In that way, a value from a monthly extreme minimum (or maximum) temperature series indicates the average of the daily minimum (or maximum) temperature for that month. And a value from a monthly precipitation series indicates the sum of precipitation for that month.

Context

Reliable assessment of recent climate trends requires observed climate time series in which variations reflect only climatic changes. Such records are referred to as homogeneous climate series . However, weather stations are subject to various non-climatic influences – including instrument changes, modifications in observing practices, relocations or surrounding changes – that can introduce artificial discontinuities known as inhomogeneities or breaks into observational data.

To address this challenge, long-term temperature and precipitation time series in Belgium were processed to produce homogenized datasets suitable for robust climate trend analysis (NOISELESS - HomogeNization Of hIStorical BELgian timE SerieS). These corrected data serve as essential reference material for assessing Belgian climate trends. It is important to note that the implemented corrections target abrupt shifts in the climate series but do not address gradual biases.

Regional climate series are also provided as supplementary information on common climate signals over broad geographic domains. Users should note that the reliability of such regional climatological series depends heavily on both the variable analyzed and the region defined. Consequently, we recommend that users without specialized climate expertise avoid drawing broader conclusions from regional series alone.

The methodology for producing regional series is documented to demonstrate how the individual station-level homogenized series can be combined to extract climate information at larger spatial scales. We encourage users to construct their own regional series based on the boundary definitions most relevant to their research objectives.

The Product User Guide (PUG) provides technical guidance on the homogenized temperature and precipitation series for Belgium (NOISELESS) dataset. Specifically, it includes:

  • A description of the data products, including station level and regional series
  • Detailed documentation of the homogenization methodology, including clustering procedures, outlier control, break detection, and correction protocols
  • Information on input data aggregation, event metadata classification, temporal and spatial coverage

Additional Note

This dataset was produced under the NOISELESS project, part of the C3S National Collaboration Programme. It was developed with support from the Copernicus Climate Change Service (C3S), implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) on behalf of the European Commission.

Data and Resources

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Categories

Authors

  • Royal Meteorological Institute of Belgium
  • Belgian Climate Centre

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Additional Info

Cite this dataset as Royal Meteorological Institute of Belgium. (2026). Monthly homogenized temperature and precipitation series for Belgium (Version 1.0). https://doi.org/10.83248/hmcf-nd77. [Dataset].
Contact
Publisher
  • Belgian Climate Centre
Temporal Coverage
  • Start: 1880-01-01 - End: 2024-12-31
Spatial Coverage
  • Coverage: Belgium
    URI: https://sws.geonames.org/2802361/
    (Bounding Box: {"type": "Polygon", "coordinates": [[[2.54, 51.51], [6.41, 51.51], [6.41, 49.49], [2.54, 49.49], [2.54, 51.51]]]})
Themes
  • Environment
  • Regions and cities
Source metadata