When selecting the site location through the wizard in ApLocate you are actually selecting the design weather data location.
The design weather data is not taken from the simulation weather file, but instead from ASHRAE weather data that you select via the selection wizard. Design weather data is used for sizing calcs (CIBSE or ASHRAE Loads) only. This data is taken from ASHRAE Fundamentals handbook.
The ASHRAE Database we use for Design Weather Data only contains monthly max/min temps for each location. The Simulation Weather Data files used by ApacheSim requires hourly data for each day for an entire year. ASHRAE don’t supply files for all locations with this kind of detail.
If there are no suitable simulation weather files for your location then have a look at the following page on our website which has some information on sourcing weather data: www.iesve.com/support/weatherfiles