Climate data

Weather and climate data underpin many engineering studies: building energy simulations, comfort studies, system sizing, wind analyses, and climate change adaptation.

However, these data do not all answer the same questions. A weather station describes what was observed at a given location; a forecasting model attempts to predict the weather over the next few days; a reanalysis reconstructs the past climate consistently; and a climate projection explores how climate may evolve over several decades.

These approaches complement one another. Depending on the purpose of the study, the aim may be to represent an average climate, reproduce an actual observed year, analyse an extreme event, or construct a plausible future climate.

Observed climate and weather

How is weather measured? How does weather forecasting work? What are reanalyses such as ERA5? How are these data converted into hourly weather files that simulation software can use?

The Observed climate and weather page covers observations, weather models, reanalyses, and files representing the current climate: Typical Meteorological Years (TMY) and Actual Meteorological Years (AMY).

Future climate and adaptation

A climate projection is not a forecast of the weather on a specific day in 2050 or 2100. Instead, it describes how the statistical properties of climate may change: average temperatures, frequency of hot days, precipitation, droughts, and extreme events.

The Future climate and adaptation page introduces climate scenarios, global and regional models, CORDEX, DRIAS, the TRACC, and the construction of future weather files for engineering studies.

Heatwaves

Heatwaves are particularly important in studies of comfort, overheating, and the resilience of buildings and urban spaces.

The Heatwaves page explains the different definitions of a heatwave, how to detect one in a weather series, and how to construct a weather file representing a future heatwave.