Wireless Sensor Networks (WSN) allows large scale deployments for environmental monitoring applications especially in the Wildland Urban Interface (WUI) (i.e. in areas where forests and rural lands interface with homes, other buildings and infrastructures). In such areas early fire detection is of great importance as the consequences of a fire are catastrophic. Towards this direction the SCIER1 project envisages the deployment of Wireless Sensor Networks at the WUI using a multi-level scheme of data fusion to enhance the performance of the early fire detection process.