Book your next international flight before prices really take off.

While buying a domestic airline ticket 70 days in advance snags the best deals on average — sometimes to the tune of $200 less — the best window to jet-set across the globe for less varies widely by region. So CheapAir.com crunched more than 917 million airfares covering more 1 million international trips to 3,000 international markets over the last year to determine when exactly U.S. travelers can save the most money flying to each spot.

The 2018 International Airfare Study released Thursday defines the “prime booking window” as the range of days during which you’re most likely to see the lowest fares; the sweet spot when it’s not too early to get a good deal, but also not too late to grab a bargain — not to mention a seat. You can jet to Mexico and Central America for as low as $489 on average if you book about 70 days from your travel date, for example, but the best time to buy your tickets to the neighboring Caribbean is about 207 days out from your travel date, for $545 on average.

ALSO READ: This is exactly how many days in advance you should book a domestic plane ticket

“International flights cost two and a half times more than domestic flights on average, so getting the timing right can really pay off,” said Jeff Klee, CEO of CheapAir.com, in a statement. “Each travel region is different, but with the data we crunched, you can book within range of the lowest fare with proper planning.

“If the price drops after you book with CheapAir.com, we also cover the difference up to $100,” he added.

But keep in mind that large festivals, international sports events and major holidays can shake these generalizations up. So if you’re planning to fly to Munich for Oktoberfest, for example, or to visit India during Holi, you may want to book even earlier than the booking window.

(CheapAir.com)

Here’s how the study breaks down when U.S. travelers can score the lowest airline ticket price for each international region.

Caribbean

  • Prime Booking Window: 36 to 321 days in advance
  • Least expensive day to book: 207 days from departure
  • Average Low Fare: $545
  • Least expensive days of the week to fly: Tuesday and Wednesday
  • Tip: Avoid holidays and fall hurricanes, and fly in January after the holidays for the lowest
  • average fares of around $496.

Canada

  • Prime Booking Window: 21 to 148 days in advance
  • Least expensive day to book: 66 days from departure
  • Average Low Fare: $427
  • Least expensive days of the week to fly: Tuesday and Wednesday
  • Tip: October is cheapest ($398) and often the prime time to see fall foliage.

Mexico and Central America

  • Prime Booking Window: 14 to 174 days in advance
  • Least expensive day to book: 70 days from departure
  • Average Low Fare: $489
  • Least expensive days of the week to fly: Tuesday and Wednesday
  • Tip: Take spring break in February versus March or April to save nearly $30 per ticket.

South America

  • Prime Booking Window: 37 to 320 days in advance
  • Least expensive day to book: 110 days from departure
  • Average Low Fare: $845
  • Least expensive days of the week to fly: Tuesday and Wednesday
  • Tip: Save $58 off the average price in February during South America’s summer. It’s also almost $250 cheaper to visit South America in February than it is in December.

Europe

  • Prime Booking Window: 50 to 252 days in advance
  • Least expensive day to book: 160 days from departure
  • Average Low Fare: $1,151
  • Least expensive days of the week to fly: Monday, Tuesday and Wednesday
  • Tip: Avoid June and July, which are peak months for American travelers and when prices spike. March is the best value hands down, with an average savings of $371 dollars per ticket.

Asia

  • Prime Booking Window: 40 to 231 days in advance
  • Least expensive day to book: 120 days from departure
  • Average Low Fare: $1,113
  • Least expensive days of the week to fly: Tuesday and Wednesday
  • Tip: Prices dip February through April, and September through November. Traveling in November, the least expensive month for Americans, can save $420 on average.

South Pacific

  • Prime Booking Window: 54 to 304 days in advance
  • Least expensive day to book: 197 days from departure
  • Average Low Fare: $1,708
  • Least expensive days of the week to fly: Tuesday and Wednesday
  • Tip: Avoid December, which is summer Down Under. That can cost you $550 more on average than if you travel in May, the cheapest month.

Middle East and Africa

  • Prime Booking Window: 96 to 287
  • Least expensive day to book: 199 days from departure
  • Average Low Fare: $1,238
  • Least expensive days of the week to fly: Tuesday and Wednesday
  • Tip: Fares change by an average of $119, more than any other market. Monitor closely.