The Republic of Lithuania is a member of the World Meteorological Organisation (WMO), a specialised agency of the United Nations since 1992
The Agreement on State Cooperation between the Republic of Lithuania and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) was signed in December 2004. The Agreement, ratified by the Seimas of the Republic of Lithuania, entered into force in 7 November 2005 and remained in force until 31 December 2009 At the end of the year, an extension of this agreement was signed for 2010-2011. To enter into force, it must still be ratified by the Seimas of the Republic of Lithuania. Since 8 December 2008 The Chair of the EUMETSAT Co-operating States Advisory Committee is V. Augulienė, Director of the Authority.
In 2005, the Office signed an agreement on the exchange of hydrometeorological information with the Latvian Environment, Geology and Meteorology Agency, and a programme of operational industrial cooperation for 2005-2006 with the Hydrometeorological Department of the Ministry of Natural Resources and Environmental Protection of Belarus.
In May 2006, the Cooperation Agreement between the Republic of Lithuania and the European Centre for Medium-Range Weather Forecasts (ECMWF) was signed, ratified by the Seimas of the Republic of Lithuania and entered into force 20 November. 2006
In 2007, the Service signed two new international agreements and one bilateral cooperation programme: 24 July 2007 – Agreement on participation in the European Organisation of National Hydrometeorological Services (EUMETNET) Distance Learning Programme (EUMETCAL), 11 December 2007 – an agreement to join the HIRLAM-A programme as an associate member, and 8 November 2007 – a programme for operational and productive cooperation with the Russian Federal Service for Hydrometeorology and Environmental Monitoring for 2008-2009.
In April 2008, an Operational and Industrial Cooperation Programme for 2008-2009 was signed with the Hydrometeorological Department of the Ministry of Natural Resources and Environmental Protection of Belarus.
In 2009, the Service signed a cooperation agreement with the Moldovan State Hydrometeorological Service and an agreement with the Austrian Central Institute for Meteorology and Geodynamics on the participation of the Authority in the EUMETNET SatRep satellite forecasting programme, and the agreement on the accession to the HIRLAM-A programme has been extended on the Authority’s initiative to the end of 2010. 29 December 2009 An amendment to the Agreement on State Cooperation between the Republic of Lithuania and EUMETSAT was signed, extending the Agreement until 31 December 2011 Ratified by the Seimas of the Republic of Lithuania on 12-11-2010, entered into force on 29-11-2010.
In 2010, the Service signed a programme of operational and operational cooperation with the Hydrometeorological Department of the Ministry of Natural Resources and Environmental Protection of Belarus for the period 2010-2011 and a cooperation agreement on participation in the EUMETNET programmes EUMETCAL and SatRep, replacing separate bilateral documents signed in 2007 and 2009. The HIRLAM Council’s decision to accept the Authority as a full member of the HIRLAM Consortium from 1 January 2011 is published on 13-12-2010.
On 23 December in Vilnius and on 29 december in Darmstadt, Germany the second amendment to the Agreement on State Cooperation between the Republic of Lithuania and EUMETSAT, extending the validity of the Agreement until 31 December 2013, and the Agreement on the accession of the Republic of Lithuania to the Convention on the Establishment of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and the conditions related thereto as of 1 January 2014, were signed. Also in 2011, the Authority renewed the agreement on the exchange of hydrometeorological information signed in 2005 with the Latvian Environment, Geology and Meteorology Agency.
On 29 March 2012 A programme for operational and industrial cooperation with the Hydrometeorological Department of the Ministry of Natural Resources and Environmental Protection of Belarus was signed for the period 2012-2017, and on 7 June 2012 – a programme for operational and industrial cooperation with the Russian Federal Service for Hydrometeorology and Environmental Monitoring for 2012-2014.
On 28 February 2013 a new agreement was signed with EUMETNET, extending the Authority’s cooperation with this European organisation of meteorological services until the end of 2017. and on 13 September The LHMS has joined the NORDRAD Meteorological Radar Network Multilateral Cooperation Agreement.
In addition, the Service has signed:
- bilateral cooperation agreements with:
- Czech Meteorological Institute,
- Hydrometeorological Department of the Ministry of Natural Resources and Environmental Protection of the Republic of Belarus (Discontinued from March 2022),
- Polish Institute of Meteorology and Water Management,
- Russian Federal Service for Hydrometeorology and Environmental Monitoring (Discontinued in March 2022);
- an agreement with the Environmental Protection Agency on cooperation in monitoring the status of border water bodies and exchange of monitoring data with:
- Kaliningrad Hydrometeorological and Environmental Monitoring Centre of the Federal Service for Hydrometeorology and Environmental Monitoring of the Russian Federal Service for Hydrometeorology and Environmental Monitoring (Discontinued from March 2022),
- Latvian Environment, Geology and Meteorology Centre
- A multilateral cooperation agreement (BALTMET) between the Estonian Meteorological and Hydrological Institute, the Finnish Meteorological Institute, the Latvian Hydrometeorological Agency, the Lithuanian Hydrometeorological Office, the Norwegian Meteorological Institute and the Swedish Meteorological and Hydrological Institute.
The membership in WMO and EUMETSAT, the cooperation agreement with ECMWF, the Service’s bilateral and multilateral cooperation agreements with hydrometeorological services of other countries and with international organisations, create preconditions for the continuous improvement of the quality and responsiveness of hydrometeorological information provided by the Service.
As part of international cooperation agreements, the Service exchanges hydrometeorological observation data and warnings of adverse hydrometeorological conditions with other countries, and its specialists participate in international programmes and projects.
The Lithuanian Hydrometeorological Service participates in the following international projects and programmes:
 | Europos hidrometeorologijos tarnybų organizacija | Dalyvaujama EUMETNET’o nuotolinio meteorologijos mokymo programoje EUMETCAL |
 | World Cities Weather Project | The WMO World Weather Information Service provides daily 5-day forecasts for 5 Lithuanian cities and climate data. The information is published on the website https://www.worldweather.org/“ |
 | High Resolution Limited Area Numerical Weather Forecasting Model (HIRLAM) Development Project | High Resolution Limited Area Modelling (HIRLAM) Application of the High Resolution Limited Area Numerical Forecasting Model (HIRLAM) to the Lithuanian context, development of numerical weather forecasts, and participation in the implementation of the HARMONIE forecasting model |
 | WMO CEE-WMO/GWP Associated Programme on Flood Management | Cooperation within the WMO Associated Programme on Flood Management for Central and Eastern Europe, providing information on major floods in Lithuania |
 | WMO Climate Information and Prediction Programme – CLIPS (Climate Information and Prediction Services) | Collaboration on the development of the Climate Information and Prediction System (CIS) and on climate change research, preparation of a report on climate research in Lithuania |
 | The NAVTEX programme for ensuring safe navigation on the seas and oceans | Forecasts and warnings are provided twice a day about expected dangerous hydrometeorological events in the South-East Baltic. |
 | WMO Global Atmospheric Observations Programme World Ozone and Ultraviolet Radiation Data Centre (WOUDC) | Continuous reporting of ozone and solar ultraviolet radiation measurements using the WOUDC common database |
 | Cooperation with the Czech Meteorological Institute on the development and maintenance of the CLIDATA (Climatological Database) climate data management system | A climate database has been set up and maintained to collect, organise and analyse observational data from meteorological stations, using a geographic information system (GIS) to present the data. Collecting meta-information on meteorological stations, their observations, etc. |
 | Global Climate Observing System (GCOS) | Collaboration on climate observations and analysis of climate change, participation in the Eastern and Central European Working Group. |
 | WMO World Weather Research Programme | Collaboration on research information in Lithuania |
 | WMO-supported Global Runoff Data Centre (GRDC) | Collaboration in the development of a global river runoff database, provision of hydrological observation data and meta-information on Lithuanian rivers, and access to the GRDC shared database |
| NORDRAD | Northern European Weather Radar Network | Participation in the exchange of weather radar observation data |