This chapter shows long-term data and trends in climate and climate-related drivers for each site.  It contains a brief introduction to the topic, and methods of measurements, selection of variables, and their data source. It consists primarily of a large number of figures showing long-term data for different variables.  On land, air temperature (mean, minimum, and maximum), precipitation, Palmer Drought Severity Index, and Walter-Lieth climate diagrams are selected.  In water, streamflow, sea level, ice duration, water clarity, and water temperature are selected.  Two types of graphs are included to show trends in the variables and to provide a sense of change across a range of spatial scales (continent, site) for each variable: maps at continental scale showing either the mean across years or the slope of the regression line (if significant) across time, and site-scale data through time.  Air temperatures are increasing in at least one variable (minimum, mean, maximum) for 27 of the 50 sites.  Sea level is increasing at all 11 coastal sites.  Observing these trends in climate across multiple ecosystems across continents is only possible with spatially extensive, long-term data collection and analysis, such as provided by the EcoTrends Project.