Developing real-time and near real-time systems and models based on sensor data acquisition requires efficient access to distributed data sources. This is especially true when multi-source datasets are required for a comprehensive model. For example, developing daily spatial estimations of water evaporation and transpiration requires access to weather stations, combined with satellite imagery, and potentially weather prediction models as well. Most existing online data dissemination services support dissemination with ad-hoc methods, designed for specific limited purposes. General purpose access methods, required by a broadening range of uses, become increasingly important. In this study, we examine standard Web services for sensor data and how clients can consume such services seamlessly in their applications. Specifically, we describe a prototype system that supports Open Geospatial Consortium standards and the Network Data Access Protocol standard. This system allows standard access to weather stations, which provide comprehensive, timely weather data, as well as access to NOAA GOES satellite data for real-time remote sensing images of California. The prototype provides daily reference evapotranspiration map for California. In addition to presenting the technical details of the implementation, the costs and benefits of building such a standard-based sensor data dissemination system are discussed.