Munich airport in particular is poorly connected to the railway network, and early morning departures are difficult to reach because the earliest train itineraries don't arrive before ~ 07:00 h. Much easier to catch a short flight at 06:00, arrive at MUC or FRA at 06:45 and hop on your second leg at 08:00.
Late evening arrivals face the inverse problem. The last train will leave at around 22:00...
I just looked it up at MVG.de and find S-trains from Hauptbahnhof almost all through the night every 40', the only longer gap is between 1:35 and 3:15. The same for the way back, there are regular trains from the airport until 1:24 at night and then a gap until 4:04.
Yes, but that's not what the original post was alluding to. If you live in Munich or Frankfurt, sure, you won't have a problem catching a flight at the earliest departure hour with public transit because the trunk routes city - airport are operated throughout the night.
However, if you're traveling intercontinental (or wherever, to be quite honest) and you live close to, say, Nuremberg or Stuttgart, you'll have a hard time finding a train to take you to München Hbf to catch an S-Bahn to the airport, and similarly for finding either a long-distance train to Frankfurt Flughafen Fernbahnhof or a feeder to the S-Bahn at Frankfurt Hbf in the middle of the night. So unless you want to pay for an overnight stay in Munich or Frankfurt or
spend the night in a train station / airport departure hall (at least free
), you might prefer catching one of these hub feeders, precisely for a lack of viable public transit options.Example
: Coincidentally exactly a year ago (Jan 8th 2019), I was booked on the 8:30am United flight out of FRA to Chicago. Being an intercontinental flight, I intended to be at FRA 2.5 hours before departure, which translated to 6am.
Now, in the grand German scheme of things I really don't live far from Frankfurt, closer than both the Nuremberg and Stuttgart metro areas. During the day time, it's very easy for me to take a commuter train to Mannheim (~15 mins) and connect onto the ICE (~35 mins) to get to FRA, which is the least stressful and fastest way to reach the airport from my location. The first trains on this line only begin to run around 5:30 though, so even catching the first one would have me at FRA later than intended with a tight connection at Mannheim, meaning that if I miss that one, I'd be in a big hurry, because early in the morning the ICEs don't run as frequently as during rush period (when it's roughly 20-minute intervals).
So if I had wanted to be guaranteed to arrive on time, my choice would have been to take the last commuter of the day to Mannheim at 1am, then connect onto the sole middle-of-the-night ICE/IC around 2:30, which would mean I could spend the rest of my night sleepless in FRA until the UA counters would open. Not an option. Luckily, I had someone who could drive me, but if I had lived closer to Stuttgart, it might have been entirely impossible and I might have to rely on taking the hub feeder from STR to FRA.