When to book Boston - Paris for June 2024?

You can use Google flights to check prices for now, but then click the toggle button so that you receive notifications if the prices for that route change. It's a very handy feature. It will also tell you when is the cheapest time to book. For more info on that, visit this post: https://community.ricksteves.com/travel-forum/general-europe/new-google-flights-feature-to-reveal-cheapest-time-to-book

Were you aware France is hosting the Olympics in July and August? Or maybe you are searching for flights to attend? I’m assuming lots of travelers are adding pre and post time in country, plus all the logistics set-up required months in advance has made flights and hotels expensive since they became available.

Tickets will likely not reduce in price. It will be very crowded. If you can be flexible, look for alternate travel dates in France. Or places.

https://community.ricksteves.com/travel-forum/france/2024-summer-flights-to-paris

I believe you asked this same question a bit earlier , so you know the Olympics are in France next summer. Perhaps fly into London and get to Paris by rail?

Good luck and have a great trip!

Brussels is another option