Weather Stations - Concepts

If the Perez All-Weather Sky Model is selected for describing the sky conditions present for the specified site location/date/time combination, the sun, sky and atmospheric data will come from the selected Weather Station. The Perez All-Weather Sky Model is an industry standard for daylighting calculations and is based on data collected from Weather Stations all over the world, usually over many years. The data supplied are not necessarily an average for that date and time at that location, but rather the data for the date that best represents typical weather for that date.

The stations are listed in order of closest to farthest, with respect to the site location (latitude and longitude).

Usually, the selected Weather Station should be the one that is closest to the site location. But this isn't always the case. If a site is near a mountain range and the closest weather station is in the mountains, the weather data for the station may not be representative of what the site location will experience. A station that is a little further away but not in the mountains may be a better choice. The user must decide whether to select the closest weather station or a different one. Knowledge of the local geography is essential to making a proper selection.

By default, Weather Stations and associated data are stored in [ProgramData]\Lighting Analysts\Shared\WeatherDatabase.db. This database is used by both AGi32 and ElumTools.

For information on downloading and installing the Weather Database, click on the Procedures tab at the top of this topic.