Big Jump in Airline Tix Prices (Bay Area-Portugal)

Yes, it's common. I don't know how many data points you have by now (3-4?) but prices change all the time and you can see a wide range of increases (not-so-steep to very steep) depending what time frames you are comparing. After you track prices for some time, you'll have a good feel of where your comfort spot is in terms of ticket price (you'll know roughly what the range looks like, although no one knows what the true "bottom" is because everyone's always wondering if they've reached dit or not).

My advice is not to be tied to a certain airline or itinerary. If you're flexible and can see multiple ways of getting there (using different dates, airlines, even airports), you're more likely to get a better fare.

I don't know your exact travel dates and I assume by Bay area you mean San Francisco . I just checked Google flights for dates in June and it looks like about $1600 per ticket into Lisbon and out of Oporto. That's on American Airlines.

I'm not a frequent flyer, but experienced something similar this month tracking flights into Vienna and out of Venice for June. Instead of fluctuating, they seemed to just be going up and up and up. The flights I originally wanted went up over $500 per ticket over the course of several weeks. Occasionally I would see something else that was pretty good....but by the next day it would have gone way up in price too.

Yesterday I found a fare I could live with -- not as low as the first fares I saw, but much lower than most of the subsequent fares, with an itinerary I actually liked -- and I grabbed it. It was an option that had previously not even shown up on the airline's website. I feel relieved to have ticketed and ok with what I paid. If you are willing to wait it out a little and just keep checking and rechecking all the sites daily....and then when you see what you want, grab it immediately, it might work for you too.

I'm not sure why things seem so crazy right now. Good luck!

That's a painful fare. I'd definitely keep watching, and I'd be exploring the possibility of a budget-airline flight (who flies from Oakland--is it Norwegian Air Shuttle?) to a northern European city, an overnight there (sorry!) and a budget flight on to Portugal the next day. You might need to do the same thing at the end of the trip. I think there's a decent chance, though, that you'll get another shot at much lower fares.

You are operating at a disadvantage in that--unlike trips into central Europe--you really don't have a good alternative to flying into Portugal itself. Ground transportation even from Spain is generally just too slow, though I guess it wouldn't hurt to check the possibility of returning from Santiago de Compostela (nice) or Vigo (nothing much to recommend it) rather than Porto. That transfer is awkward enough that I'd want to save at least $150 before flying back from Spain, I think. Definitely watch round-trips into Lisbon as well as Lisbon/Porto multi-city flights.

My initial thought for this year's trip was that I would fly from Washington to Munich in early May, then back from London much later. I've changed my mind, but I haven't turned off the Google Flights fare alert. I've lost count of how many times the fare has bounced from about $830 to about $1330. I know it has gone through at least five such cycles, maybe as many as eight or ten. Sometimes it stays high for just a couple of days. It's hard to understand what sort of algorithm could cause repeated changes of that magnitude. I see that it's low today; too bad I no longer plan to fly into Munich.

Check out Norwegian Air out of Oakland and then a low cost carrier from any number of European cities. They fly directly into Gatwick, Barcelona, Paris, Amsterdam, Oslo, and Stockholm (and probably more by now.)
Oakland is convenient with direct BART access and returning from Europe it is usually less hectic at passport control.
The planes are new and pretty comfortable. Just be sure to read (and re-read) the fine print and leave enough time between flights. They will weigh your bags, so if you don't pay to check a bag in advance you will either wish you had or pay a lot at the airport. (On my last flight I had my iPad mini and 3-1-1 bag in my jacket pockets!)
Another option if you must leave from SFO is WOW Airlines. I haven't flown them but a friend has and thought it was fine.
Good luck!

I'm in the Bay Area as well and just a few weeks ago found a great price nonstop from Oakland to Barcelona on Level by Iberia. If you're willing to spend a night or two in Spain, you could look into flying from Barcelona to Lisbon. SFO to Paris has also been cheap lately.

The name of the airfare game is to run all permutations, including less than logical possibilities. Too often from the hinterlands where I live, it's cheapest to fly to a major airport like Frankfurt (airport code FRA) and then use a budget carrier for the final leg. Give yourself plenty of time in case of travel delays.

Usually the multi-city (i.e. open jaw) approach is a good one. Sometimes it makes sense to backtrack to your arrival city especially if it is not too far away. For example, I think you will find a round trip to Lisbon to be cheaper than SFO-LIS/OPO-SFO.

As others have mentioned, it would be good to consider the cheapest flight to a major European city from San Francisco, then a budget carrier to/from Portugal. I would pick a major city that you would like to visit and that has good service to Portugal. London and Paris come to mind.

We have used Aer Lingus lately to fly to Europe. Sometimes we stay in the Dublin area at the beginning or end of the trip.

Haven't checked, however Norweigian flys to Madrid through Gatwick; you can then p/u bags and fly Vueling or Iberia to either Lisbon or Porto.
last year we did that from Boston, however, stayed a couple of days in Madrid.

I'd keep watching. One of the best tips I ever learned (outside of clear your cache and browser, which you already did!) was to vary the time of day that you check fares. I read of one person checking the same fare, four times a day, every day. While that seems a bit obsessive to me, it worked for them and resulted in some lower fares.

I'd hold before I paid $9400 for those tickets.

Thank you for all the good feedback and suggestions. I like the Plan B suggestion of flying into more of a European hub and then catching a budget flight from there.

Thank you for all the good feedback and suggestions. I like the Plan B
suggestion of flying into more of a European hub and then catching a
budget flight from there.

Lesson learned on that one. When you see an airfare that works with your budget and schedule, buy the tickets then and there. Especially with airlines, pricing is dynamic meaning fares can change minimally or drastically within minutes. I've seen it too many times. Glad there is a Plan B and I hope you have a wonderful trip.