With warm temperatures and school out of session, summer is a popular time for travel.

But for those with flexible schedules or those who prefer low-season travel, Europe is proving to be an affordable Fall destination, with roundtrip flights departing from the US currently under $400.

Flights to London, Paris, Madrid, Barcelona, Rome and Scandinavian cities like Copenhagen, Stockholm, and Oslo are currently the cheapest. Other European cities may be added to this list as the fall season nears. 

Comparing airfare from summer to fall shows that prices will drop significantly, with flights departing from Chicago to Barcelona only $391 in mid-September (compared to $1,075 in August), and flights from Los Angeles to Rome only a few dollars more at $396 roundtrip in late September (compared to $927 in late July). 

To take advantage of these deals, head to your favorite airfare comparison sites like Skyscanner or FareCompare. If you’re flexible, you can search for the entire month of September and October to see which days are the cheapest.

It’s likely these prices will increase as the dates get closer, so buy soon if you’re want to take advantage.