The short answer is in stock form, the fan either comes on at 221F or 194F based on a handful of operating conditions.
The long answer is it depends (at least on the 1.4T). The ECM has a table of values it uses based on RPM "zone" and Torque "zone" vs coolant temp AND has a different set of values based on actual vs desired coolant temp. Then of course, AC pressure has another set of values that control the fans. Both the RPM and Torque zones are customizable in EFILive/HPTuners.