About Us

Welcome to the webpage of the Climate Limited-area Modelling Community!

The CLM-Community (Climate Limited-area Modelling-Community) is an open, international network of scientists, who develop and apply the regional climate models COSMO-CLM and ICON-CLM.

To become a member of the CLM-Community please follow the information here:


The CLM-Community currently has around 250 members from about 80 climate research institutions all over the world. It is, to our knowledge, the largest consortium in the field of regional climate modelling in the world, aiming to address the challenges of model development, to efficiently use the computing resources and to make substantial contributions to answer the key questions of regional climate modelling. 

The CLM-Community members meet every year at the  in September. At the assembly, recent developments and exciting results are presented, further cooperations in working and project groups are initiated and community decisions are taken.

ICCARUS (ICON COSMO CLM ART User Seminar) is the second imporant meeting for the CLM-Communtiy. It takes place each year in spring at the headquarter of the Deutscher Wetterdienst (DWD) in Offenbach, Germany. ICCARUS is organized together with the ICON-, COSMO- and ART-Communities. At ICCARUS, recent model developments are presented in joint plenary sessions and in more detail also in project and working groups of the different communities.

Usually, shortly after ICCARUS, the annual takes place in the DWD training centre in Langen (Germany) for one week. All new users of ICON-CLM are invited to this training course to get assistance with the first steps in regional climate modelling with ICON-CLM.





The COSMO model in CLimate Mode (COSMO-CLM) is based on the "Lokalmodell" (LM), which was developed at Deutscher Wetterdienst (DWD) in 1999. In 2005 COSMO-CLM became the Community-Model for regional climate research in Germany. Since 2007, a unified version of the weather forecast model COSMO (COnsortium for SMall scale MOdeling)  and COSMO-CLM exists (COSMO 4.0). The CLM-Community and COSMO cooperated closely in the following years. The unified model version COSMO 5.0 for weather, climate, and environmental research was released in 2014 and the last version of the COSMO model (COSMO 6.0) was released in December 2021. 


The CLM-Community currently recommends COSMO_5.0_clm6 for regional climate modelling applications. It is distributed with a recommended configuration for the European domain.


COSMO-CLM is an atmosphere model coupled to the soil-vegetation model TERRA. Additionally, there is the possibility to use COSMO-ART (Vogel et al., 2009), which enables the calculation of the interactions of trace gases and aerosol with the atmospheric radiation. COSMO-CLM has also been coupled to the regional ocean model NEMO for the North and Baltic Seas as well as the Mediterranean Sea. NEMO also includes a sea ice module. Other regional processes in the climate system like the ice sheet dynamics, plant responses, aerosol-cloud interaction, and the feedback to the GCM driving the RCM are still prescribed or neglected.

The main purpose of the CLM-Community is communication and exchange of information to provide a platform for collaboration and joined research and to enable a harmonized model development. There are several ways to share and exchange information at the moment:

  • this community portal

  • the biannual published newsletter

  • our regular meetings


    the forum  to post and answer questions
  • the wiki 🔑


If you are interested, you are cordially invited to be part of our exciting community: