The growth in number of Earth sensors and increase in data volumes have raised a problem of observations integration, data analysis and reasoning over the integrated data. The two initiatives are building an interoperable environment for Earth observations: the Sensor Web Enablement and the Semantic Sensor Web. The standards for web services and observation encodings are resolving syntactic interoperability between sensors. The Semantic Web standards are enriching observations with description of data semantics and thus improving data integration. The paper demonstrates the building of Semantic Web for Earth observation data. It explains development of meteorological data ontology and provides an example of transforming meteorological data into Resource Description Framework data model. Although at the very beginning, the current implementations have proved the Semantic Web as an emerging technology for Earth observations integration and web computational modelling.