RNCEP: global weather and climate data at your fingertips

1. Atmospheric conditions strongly influence ecological systems, and tools that simplify the access and processing of atmospheric data can greatly facilitate ecological research. 2. We have developed RNCEP, a package of functions in the open-source R language, to access, organise and visualise freely available atmospheric data from two long- term high- quality data sets with global coverage. 3. These functions retrieve data, via the Internet, for either a desired spatiotemporal extent or interpolated to a point in space and time. The package also contains functions to temporally aggregate data, producing user- defined variables, and to visualise these data on a map. 4. By making access to atmospheric data and integration with biological data easier and more flexible, we hope to facilitate and encourage the exploration of relationships between biological systems and atmospheric conditions.