Airfare to Europe from LAX

To the person answering the question please also let us know how to pick winning million dollar lotto numbers.

To OP - there is no 'magic' day,time, month, to buy airfare.

The best place is from the airline itself.

Don’t we all wish there was. Good luck.

Try tracking Google flights but make the reservations thru whichever airline meets your needs.

I would start a spreadsheet now and start tracking, that is the only way to determine "reasonable". You may also want to attack it by just getting to Europe, pick the cheapest destination, then purchase a flight from that destination to your desired place. You can use Google Flight's and choose "explore" and see what comes up.
We Fly from LAX also and usually fly Aer Lingus or Air Canada, with layovers in Dublin and Toronto. My friend just found some great fares on Turkish Airlines.
Subscribe to Travel Zoo, as they will give you heads up on any deals on flights to Europe, Same with Going (formerly Scotts Cheap Flights).

https://www.bbb.org/us/co/boulder/profile/discount-stores/scotts-cheap-flights-inc-1296-1000117125

Only a little imagination needed to understand the name change

Just out of curiosity where are you flying to in Europe & is it open leg or back from same place? In addition to Travelzoo, which I've also used successfully, you could also sign up directly with the airlines for specials. For this autumn and early next spring, I've seen some great sales on United, SAS & British Airlines to a number of European destinations. Unfortunately, May is already a busy season, so if there's any chance of moving the trip up a month you might save big time & good luck! Let us know if you find any great deals....

Norse Atlantic has inexpensive, nonstop flights from LAX to Oslo. From Oslo, you can continue onward to cities throughout Europe. Flights during May will be less costly than June.
You can sign up for fare alerts on www.Skyscanner.com and at GoogleFlights.

Start tracking the price for the airfare. Not sure what reasonable price to you is. I started tracking airfare Seattle to Dublin a few months ago, my trip is Aug 2024. Then one day I saw a great price at Icelandairair. $658. I immediately bought it, and never looked back.

Norse Atlantic just announced a new route from LAX to Paris a few days ago.

https://thepointsguy.com/news/norse-atlantic-airways-los-angeles-paris-cheap-flights/

Norse Atlantic advantage? Price.

Norse Atlantic disadvantage? If a flight gets cancelled, the airline may not be able to get you on another flight for a day or two, which obviously impacts your vacation.

“i immediately bought it, and never looked back.”

That’s the key. Track fares until you feel comfortable buying, buy, and then don’t look any further!

Aer Lingus has low fares too.
We got tickets SF-Paris for $695 in January.
Can’t wait for Norse to start flying out of SF in May.

SAS has some good prices at the moment, even if you just missed their sale. https://www.flysas.com/us-en/low-fare-calendar/