Weather data is necessary in many Building Simulation activities. There are a number of useful sources of both synoptic and hourly climate data. Synoptic data is provided in design guides such as the CIBSE Design Guide A and J. Hourly data, in various forms, is available for many hundreds of sites world-wide. General guidance is available at: http://gundog.lbl.gov/dirsoft/d2weather.html A useful source of hourly climate data in the IWEC format is http://www.eere.energy.gov/buildings/energyplus/cfm/weather_data.cfm . TMY2 format data is available from http://rredc.nrel.gov/solar/old_data/nsrdb/tmy2.

Weather data can also be purchased from national weather organisations. Weather from the UK met office has been processed for building simulation purposes by CIBSE and can be obtained by purchase of CIBSE Guide J.