Open data manual

FMI has decided to publish a major part of it's meteorological and oceanographic datasets as Open Data using open standard web service interfaces for geospatial data. This evolving documentation is intended to give a good head start on developing applications using weather and oceanographic data through the FMI's open data web services. The initial version of these pages will be ready by 6th June 2013

FMI's  Open Data datasets are published using open standard web service interfaces for geospatial data defined by the Open Geospatial Consortium (OGC). The data opening is part of the growing global trend of publishing environmental information as Open Data, and is part of the implementation of the open data policy of the Finnish Government and the EU INSPIRE directive.

The meteorological datasets are inherently different from many other traditional geospatial datasets: The data volumes gathered from weather measurements stations and using remote sensing instruments like weather radars and satellites, or produced by numerical weather forecast models are huge and continuously changing: A radar image retrieved 15 minutes ago has already been succeeded by two or three more recent images, and the precipitation forecast fetched yesterday for tomorrow should be replaced by today's forecast to get an accurate prediction. For this reason it has been decided to offer the continuously updated environmental observation and forecast data as services rather than static data sets.

FMI's Open Data Services are divided into three categories following the categorisation used by the INSPIRE directive:

  • Discovery Service (a.k.a. Catalog service) provides metadata about the available datasets and services, implemented using the OGC Catalog Service for Web (CSW),
  • View Services give a visual preview of the available datasets, implemented using OGC Web Map Service (WMS), and
  • Download Services provide a continuous online access to the most up-to-date data, implemented using OGC Web Feature Service (WFS).

All these services are intended to be machine-accesible: in most cases the data users interact with these services only through applications provided by FMI, the data users themselves or third parties. In other words, FMI is providing APIs for accessing the data.

Using open standard interfaces makes it easier for developers to build re-usable software being able to access many datasets from different data providers and combine them together to create new interesting and technologically advanced applications. FMI encourages both small and large developer individuals and organizations to experiment with the provided datasets and publish their creations either as free or commercial products. The data users must agree to the FMI Open Data Licence and register to get access to the services.


Registration for API-key is required to use open data service interfaces.

Services contain API-key specific request limitations:

  • Download Service has limit of 20000 requests per day for a single API-key
  • View Service has limit of 10000 requests per day for a single API-key
  • Download and View Services have combined limit of 600 requests per 5 minutes for single API-key

Quickstart for accessing time series data

First step

  1. Register to get API key (temporarily in Finnish only)
  2. Capabilities inform what operations may be requested
  3. List stored queries that can be used to get data
    2. or for more details
  4. Get some feature data as XML
      1. API key (step 1) is used as part of the URL path
      2. Capabilites (step 2) informed that getFeature operation can be used for query
      3. Stored query list (step 3) provided value options for storedquery_id


MetOLib is a JavaScript library that provides implementation of API classes that may be used to request weather data from the Web Feature Service (WFS) server of the Finnish Meteorological Institute INSPIRE Atmospheric Features and Geographical Meteorological Features guidelines compatible WFS Download Service server at

MetOLib provides a good JavaScript reference implementation for WFS requests. MetOLib can be used to request data from server and to get parsed XML data as JavaScript objects. Also, MetOLib provides cache for requested data.

Get MetOLib from GitHub. MetOLib readme file gives information on how to get started.

An example implementation can be found on

Notice, API-key is required for queries. Register for API-key.

MetOLib example

See API documentation and comments from source code to get more information about functions and parameter objects.

var SERVER_URL = "";
var STORED_QUERY_OBSERVATION = "fmi::observations::weather::multipointcoverage";
var connection = new fi.fmi.metoclient.metolib.WfsConnection();
if (connection.connect(SERVER_URL, STORED_QUERY_OBSERVATION)) {
    // Connection was properly initialized. So, get the data.
        requestParameter : "td",
        begin : new Date(1368172800000),
        end : new Date(1368352800000),
        timestep : 60 * 60 * 1000,
        sites : "Helsinki",
        callback : function(data, errors) {
            // Handle the data and errors object in a way you choose.
            handleCallback(data, errors);
            // Disconnect because the flow has finished.