The Global Historical Climatology Network – Daily dataset provides a strong foundation of the Earth's climate on the daily scale, and is the official archive of daily data in the United States. While the dataset adheres to a strict set of quality assurance, no daily adjustments are applied. However, this dataset lays the groundwork for other products distributed at NCEI-Asheville, including the climate divisional dataset (nClimDiv), the North American monthly homogenized product (Northam) and the 1981-2010 Normals. Since these downstream products already provide homogenization and base period schemes, it makes sense to combine these datasets to provide a sub-monthly monitoring tool for the United States.
Using these datasets already in existence, monthly adjustments are applied to daily data, and then anomalies are created using a base climatology defined by the 1981-2010 Normals. Station data is then aggregated to the state level and then regions defined by the National Climate Assessment. Ranks are then created to provide informational monitoring tools that could be of use for public dissemination. This presentation goes over the product, including methodology, latest results, validation schemes, sources of uncertainty, and addressing future steps. It also provides an assessment of selected notable recent extreme events.