When Southwest first started flying, it was an entirely short-haul airline. This shouldn’t be a surprise, nor should it be a shock that Southwest would begin flying longer distances over time. Despite that, it still makes me do a double take when I see just how much things have changed. I thought you’d enjoy a stroll through the wayback machine with me as we take a look in more detail.
I went all the way back to 1990 using Cirium T100 and schedule data to when Southwest was still a little guy, just barely getting out of its Texan comfort zone with Phoenix flying. Back in May of that year, nearly 90 percent of the airline’s flights were under 650 miles. You can see how things have changed in this chart.
Southwest Pct Departures by Flight Miles 1990 – 2021

Not much did actually change in the first five years or in the 1990s at all. When I started college in Washington, DC in 1995, my parents lived in Phoenix and I would go back and forth. Flying Southwest always meant a two-stopper to get to Baltimore back then. I can remember going through Oklahoma City, Tulsa, Omaha, Kansas City, St Louis, Chicago… you name it.
It didn’t change much by 2000 either. Sure, Southwest started dabbling in longer hauls, but it wasn’t until 9/11 that things shifted dramatically.
After 9/11, the massive shift in security procedures really hampered short-haul demand. Those quick trips were no longer so quick. Travelers had nightmare stories of required early airport arrivals, long security lines, general hassles, and eventually… the liquid ban. People who used to fly started thinking, “screw it, I’ll drive.” And Southwest responded.
The next big shift came after Southwest acquired AirTran. That introduced international flights which were naturally longer and that moved the share needle again. It has only accelerated from there.
On the chart, I included May 2021 which is a mostly-final schedule along with September 2021 which wasn’t filed long ago but is more of a wish list of a schedule that will be refined later. As you can see, there is a significant difference in the share of short-haul between these two months. During COVID, short-haul flights have again been impacted with people opting to travel by car even more in order to stay away from others. Southwest obviously hopes some of those short-haul flights will come back, and they will to some extent. But Southwest is now a very different airline.
You’re probably wondering about the detail here. While I can’t go through every route, I did pull some maps together. I would have liked to show 2000 since it was before 9/11, but the Cirium schedule mapper doesn’t go back that far. Instead I compared May 2005 to May 2021. Let’s start with flights under 650 miles.

The first thing that jumps out to me is the inclusion of Denver in 2021 when it didn’t exist in 2005. That was quite the hole back then. You also see the significant infill in the east as the airline kept growing. Then there’s the west and Texas whee it actually looks like connectivity in short-haul land has decreased. (A quick note: I left intra-Hawai’i flying off the map, but it does exist.)
It’s important to remember that Southwest has grown like a weed since 2005. Just because short-haul’s importance in the network has declined doesn’t mean that it has actually cut the number of flights overall. Everything at Southwest has grown, but some areas have grown differently than others.
Now let’s move on to mid-haul flights from 650 to 1500 miles.

Back in 2005, mid-hauls were largely part of an east-west network with the only significant north-south being focused on Florida or Phoenix/Vegas.
Today, well, you can’t even see the routes because there are so many of them. You can, of course, see the international flying that didn’t exist in 2005, but that looks like a rounding error compared to the sheer density of routes within the US.
This shows how Southwest’s network really shines. By connecting all these mid-size cities to each other, Southwest has created a blanket over the US that makes for great utility for travelers in every city it serves. Sure, you can point out some “hubs,” but it really is a mesh that covers the country.
Lastly, we’ll look at the flights of more than 1,500 miles.

You might have expected to see huge growth here, but the primary bump is the addition of Hawai’i and Caribbean flying. Outside of that, sure there are some more routes over the continental US, but it’s not really that significantly different, especially compared to medium haul.
What I notice is the sparsity of routes in the east. Transcon is not in Southwest’s wheelhouse, but take that line from Chicago down and you have a whole lot of west coast flying from there. It’s just those slightly longer flight that don’t quite work as well for the airline.
Back in the day, Southwest was a short-haul airline at heart, but as demand has shifted, it’s the medium-haul flights that have become the new heart of the airline. Despite the addition of some very short-haul flights like Colorado Springs – Denver meant solely for connections, it’s unlikely that the airline’s sweet spot is going to change any time soon.