Fastest marathon course: Berlin or Valencia?

Berlin alone. fast and good weather to race

Having run both (Berlin 4x, Valencia 1x) I can say there’s really not much in it. Course wise they’re both pancake flat. Berlin has had some unfortunate weather in recent years but it’s usually perfect. Valencia weather great too, but it can be very windy.

For what its worth, the Valencia course has a lot more turns than Berlin. You won’t really notice them all that much, but if you compare both course maps you’ll see what i mean. The Valencia 2021 edition definitely was windy, but you’re surrounded by buildings most of the time so it wasn’t that big a deal at all.
I actually find the weather in Berlin more of a risk factor, as it can be very hot in Germany in September. Valencia in December usually is at 15°C.

Can’t go wrong with either. Both courses are superflat and organized very efficiently, Waterstations in Valencia were handing out waterbottles instead of cups, which i liked, but you may not.

Valencia is less exposed and the weather is usually more predictable.

Berlin, the organisation and start area is a mess.