Find your weather data sets

There are two main data types available:

• TRYs for energy assessments and,
• DSYs for overheating assessments.

If you are carrying out another type of assessment, please ensure the CIBSE Weather Data is appropriate for your intended use.

For more information about CIBSE Weather Data please see our Technical Briefing document and the FAQs section.

2030s CIBSE Weather Data (2025 Release) are representative of the time period between 2019 - 2039. These should be used to assess current energy usage and overheating risk.

Future CIBSE Weather Data (2025 Release) contain weather data that cover two additional time periods. These consist of:

• 2050s representative of 2039 - 2059
• 2080s representative of 2059 - 2089

These are intended to be used for stress testing building designs for overheating risk and evaluating the future energy requirements of a building.

For more information about CIBSE Weather Data please see our Technical Briefing document and the FAQs section.