United Airlines has Vienna and Berlin on sale for $685 to $693 round trip for travel from August 23 to December 12. These fares are available nearly all dates during that time frame. One of the more interesting itineraries to me is San Francisco to Newark or Chicago for Austrian Airlines EWR/ORD-VIE flights.
United Airlines/Austrian Airlines
San Francisco SFO – Newark EWR – Vienna VIE – Chicago ORD – SFO
$692.26 Wed August 24 – Sat Sep 3 (Google Flights link).
There have not been many discount fares to Europe this past week from San Francisco or LAX. I keep seeing low fares with American and United on Kayak.com/Explore/SFO, but I do not find the fares. This indicates to me the airlines are are posting low fares and expiring them within hours. I saw this a couple days ago with United Airlines in Seattle when there were a dozen airports in France, Italy and Spain on sale in the $600s and midway through writing a Loyalty Traveler post the fares went up over $1000, then 30 minutes later were back down to the $800s.
Chicago, New York and Washington DC have seen numerous deals this past week to Europe.