+ weather --build-sets
+
+Then wait, and wait, and wait some more. After loading and analyzing the
+source data, it will guess an upper-bound for the number of great-arc
+distance calculations it may have to perform and attempt to give you a
+progress bar indicating percent completion. If you're lucky, it will
+finish successfully also generate some automated quality assurance
+analysis of the results (mostly checking for obviously bad airports,
+stations, zones). If you are UNlucky, it will break, which is not
+terribly uncommon because the government-provided source data is often
+misformatted or gets sudden schema changes requiring updates to the
+parsing routines in weather.
+
+If you're using a system-wide (for example, distribution packaged) copy
+of weather and its data, you may want to place the new airports,
+stations, places, zctas and zones files into your ~/.weather directory
+and make use of the setpath configuration or command-line options to
+override where weather looks for them. See the weather(1) and
+weatherrc(5) manpages for details.