climatological

Climatological is an adjective relating to climatology, the scientific study of climate, its variability, and long-term patterns. In practice, the term is used to describe data, analyses, and concepts that pertain to climate rather than short-term weather. Climatological work focuses on typical conditions, seasonal cycles, and regional differences over extended periods.

A central concept is the climatological normal, a baseline derived from long-term observations. Normals are usually 30-year averages of selected variables such as temperature, precipitation, humidity, and wind. They are used to gauge how current conditions compare with a region’s typical climate. The World Meteorological Organization has standardized 30-year periods for normals, with common examples including 1961–1990 and 1991–2020. Normals are periodically updated to reflect evolving climate patterns and are not predictions of future weather.

Climatological data come from a mix of sources, including ground-based weather stations, weather ships, buoys, radar and satellite observations, and reanalysis products. Data are processed to create consistent records, often involving quality control, homogenization, and gridding to produce gridded climate fields or station summaries. These data underpin climate research, risk assessment, agriculture planning, and infrastructure design.

Applications span monitoring climate variability, assessing trends, and informing policy. Limitations include potential biases from uneven station coverage, changes in instrumentation, and the fact that normals may become less representative under rapid climate change. Climatology remains distinct from weather forecasting and from long-range climate projections, though it informs both.