Results/Conclusions Results show generally good agreement between MODIS and PhenoCam time series for many sites. Agreement is stronger for sites dominated by deciduous forests and weaker for more arid and conifer locations, where the underlying seasonal cycle is less pronounced. PhenoCam data are also sensitive to the camera field of view and the sub-region of images used to generate time series. Camera placement, maintenance, and to some extent calibration also affect the overall data quality. Preprocessing of camera data (filtering and smoothing) is required to optimize signal-to-noise ratios and fill gaps. Our results show that data from networked digital cameras provide a useful source of information for monitoring phenology at local scales, for scaling local data to the resolution of satellite data, and for assessing the quality and information content of satellite-derived phenology data sets. At the same time, more effort is required to refine methods for extracting high quality time series data from digital cameras. Naïvely ignoring these issues can lead to poor results. As these methods mature, networks of digital cameras such as PhenoCam will become increasingly useful for site-level monitoring as well as satellite validation studies.