My current theory: 'Rain' in East Thanalan has been removed from all but one entry on the weather tables. It is now designed to only pop once a week, in order to gate the Sightseeing Log content. There will be a similar log entry for every 20 logs.

Unfounded speculation, just based on current circumstances.

Also, I have heard reports of one period of Rain (not Showers) since the patch hit; 12am to 8am.