When to book flights within Europe for best deals?

I heard that for the cheap airlines, they start cheap and prices don't go down. In 2018 I booked early for a cheap flight (€50) from Heraklion, Greece to London.

Most of the value airlines have prices that generally only head in one direction unless they have a summer sale or winter promotion for a few days and these are for off season flights. The only thing to contradict this in the past 2 years has been Covid, where prices fell when lockdowns and restrictions were introduced and rocketed the day restrictions were lifted.

August is peak holiday season, so I doubt prices are going to fall. I booked flights for January 2023 last month. My October 2022 flights were booked in January.

I start checking prices 10-11 months before I plan to travel. As soon as I see a price I like, I will just book it. For my trip last Sept. Chicago to Zurich, I was able to get a great price at $885 RT. That same flight will cost me $1243 RT this June. I also have a flight to Austria this Sept. and that one cost my $939. I was happy with all 3 prices. I suggest booking now if you find a decent price. Good luck!!

Well, I'm seeing $89 on Austrian from Vienna to Paris (CDG) for Aug. 24. That's pretty good and I'd buy that now.

As for Salzburg to CPH, I would suggest taking the train to Munich and departing from there. The airport in Salzburg is small and routes are limited (making prices higher).

It's hard to say and it might be very different now compared to pre-Covid.

But for Paris-Vienna you should look at Austrian instead of Lufthansa. Or as mentioned the direct overnight train. For Salzburg-Copenhagen going to Munich by train might be a option, then you have direct flights with SAS and Lufthansa.

But, what is your general plan for this trip? From a geographical point of view it seems like you are visiting the cities in the wrong order if you want to go from Paris to Vienna, then backtrack to Salzburg before heading to Copenhagen.

Austrian Air is part of Lufthansa so you can actually book an Austrian Air flight via the Lufthansa website.

Yes, Austrian is part of the Lufthansa group, but you can still book directly with Austrian.

I have feeling as well that the OP meant to say CPH to Salzburg?

Nope, Salzburg to Copenhagen.

I did look at Munich for flights to Copenhagen. The train to MUC + a non-stop flight will end up taking much longer than a 3-hour and 10 minute connecting flight out of Salzburg. And when you factor in the cost of the train overall cost is similar, just a bit cheaper from Munich but not worth it I think.