Climatologies of weather phenomena can be quite informative regarding the variation and trends in weather features, and useful in determining the range of extreme conditions. This page presents climatologies, largely based on observational data and centered on the middle part of the United States. Some studies examining biases in long-term observational data sets also are included, especially for temperature. Most of these studies are from American Meteorological Society journals, but other journals and state or agency reports are also included. Links to the manuscript abstract are provided in most cases. This web page will be updated with climatologies from additional weather phenomena, and as new climatologies are discovered additional citations will be added.