You can’t go wrong predicting that Labor Day flights will be full. But exactly how full will they be?

Airlines for America, the trade group representing the interests of U.S. airlines, is predicting that 16.1 million travelers will fly during the Labor Day weekend (Wednesday, August 30 – Tuesday, September 5). That’s a 5 percent increase over last year’s 15.4 million Labor Day flyers.

No problem, according to A4A: “While we expect a growth in passenger traffic over the Labor Day holiday, flyers can rest assured that U.S. airlines have appropriately increased the number of seats available for their late summer getaways.”

Putting numbers to those percentages, A4A is projecting an increase of 110,000 passengers per day, which would be more than offset by an increase of 133,000 available seats per day. That means that this Labor Day’s load factors will be slightly lower than last year’s, which should provide some relief for holiday flyers, but only in relative terms. Planes will still be flying more than 90 percent full on average, and closer to 100 percent full on more popular routes. That’s a sure-fire recipe for congestion and claustrophobia.

Related: Would You Board a Self-Flying Plane?

The busiest travel days will Friday, September 1, and Thursday, August 31, followed by Monday, September 4, and Tuesday, September 5. The least busy day will be Sunday, September 3.

And the busiest airports: Atlanta, Los Angeles, and Chicago.

If you can travel on off days, from less congested airports, you stand a chance of minimizing the stress of holiday travel. Otherwise, be prepared for an extra-uncomfortable flight experience. Because Labor Day.

Reader Reality Check

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After 20 years working in the travel industry, and almost that long writing about it, Tim Winship knows a thing or two about travel. Follow him on Twitter @twinship.

This article first appeared on SmarterTravel.com, where Tim is Editor-at-Large.