Portugal has been on sale the past couple of weeks from California with United Airlines and Air Canada. This is one of the cheapest airline ticket destinations for travel to Europe this fall.
Ticket prices from SFO to Lisbon can be found for $368 to $409 round trip for travel some weeks in every month from September 2018 to March 2019.
LAX to Lisbon departures price from $400 to $440 round trip Sep-March 2019.
SFO to Porto OPO is on sale from SFO for $388 to $402 for Sep-Oct dates.
LAX to Porto is around $428 in Sep-Oct. Porto ticket prices rise in November.
This Star Alliance fare sale is also available for San Jose to Lisbon for around $380 round trip, but only September to December 2018.
United Airlines San Francisco SFO – London LHR – Lisbon LIS – Washington IAD – SFO
As an aside, I noticed Lisbon has two InterContinental Hotels, two Holiday Inns and four Holiday Inn Express hotels. This might be a great city for fulfilling your IHG Accelerate tasks. I contemplated going to Lisbon this summer to earn 60,000 IHG bonus points, but hotel prices at IHG are much lower in the fall than summer. One of my missed opportunities was not visiting Lisbon before 2017. In the past two years IHG raised reward rates at the two Lisbon Holiday Inn hotels from 15,000 points to 30,000 points.
My summer plans are taking me to Vienna, Austria instead of Portugal.
This morning I had a tough time choosing between this airline ticket deal to Lisbon and Icelandair to London for $263 round trip. Portugal has been one of my desired destinations and United flights would have advanced my Aegean elite miles for Star Alliance partner flights.
I chose Icelandair primarily due to London being one of the cities with cheap flights to Sibiu and Cluj-Napoca, Romania. Those places have Hilton hotels for 10,000 points per night.