Americans are gearing up for a record-breaking Labor Day holiday weekend with nearly 23 million seats booked, and some days and airports will be more crowded than others.

According to data from booking site Hopper, Thursday and Friday will be the most crowded days to depart at airports across the United States, Monday will be the busiest day to return. 

“We are expecting a busy Labor Day travel weekend this year,” Hayley Berg, the lead economist at Hopper, told Travel + Leisure. “If you are taking to the skies this weekend, we recommend getting to the airport early and giving yourself plenty of time to get through security.”

Overall, 22.8 million seats are booked for the holiday weekend, or 2.4 percent more than the same week last year, and 86 percent will be headed to domestic destinations. 

Hartsfield-Jackson Atlanta International Airport (ATL) – consistently the world’s busiest airport — will once again take the top spot for crowds on Labor Day weekend. The busiest time at the airport will likely be between 8 a.m. and 12 p.m.

Atlanta is followed by Chicago O’Hare International Airport (ORD) and Dallas Fort Worth International Airport (DFW), which are each expected to be most crowded in the evenings from about 4 p.m. to 8 p.m.

However, when it comes to where people want to go, Las Vegas is the most-booked destination for the unofficial end of summer with flights averaging just $210 roundtrip. Chicago was the second most-booked destination with Atlanta, Denver, and Dallas rounding out the top 5.

In total, more than 17 million travelers are expected to pass through U.S. airports, according to recent data from the Transportation Security Administration (TSA). The record-breaking weekend will cap an equally record-breaking summer.

Experts recommend travelers arrive at the airport early to avoid any travel snafus. In fact, most airlines recommend arriving two hours before a domestic flight and three hours before an international flight.

These are the top 10 busiest airports for Labor Day weekend, and when they will be at their most packed, according to Hopper:

1. Hartsfield-Jackson Atlanta International Airport (ATL): Most crowded in the mornings from 8 a.m. to 12 p.m.
2. Chicago O’Hare International Airport (ORD): Most crowded in the evenings from 4 p.m. to 8 p.m.
3. Dallas Fort Worth International Airport (DFW): Most crowded in the evenings from 4 p.m. to 8 p.m.
4. Denver International Airport (DEN) – Most crowded in the mornings from 8 a.m. to 12 p.m.
5. Los Angeles International Airport (LAX): Most crowded in the mornings from 8 a.m. to 12 p.m.
6. John F. Kennedy International Airport (JFK): Most crowded in the evenings from 4 p.m. to 8 p.m.
7. Seattle–Tacoma International Airport (SEA): Most crowded in the mornings from 8 a.m. to 12 p.m.
8. Harry Reid International Airport (LAS): – Most crowded in the mornings from 8 a.m. to 12 p.m.
9. Charlotte Douglas International Airport (CLT): Most crowded in the mornings from 8 a.m. to 12 p.m.
10. San Francisco International Airport (SFO): Most crowded in the mornings from 8 a.m. to 12 p.m.