Berlin is the course where records fall. Kipchoge’s 2:01:39 in 2018 came there on a cool, perfect morning. Tigst Assefa’s 2:11:53 in 2023 was the same story — crisp air, flat roads, everything lining up. That’s what Berlin is supposed to deliver. But not this year.
The 2025 race was hot and humid, mid-20s by the time most runners were deep into it. Sebastian Sawe went out on world record pace, hitting 5 km in 14:09, 10 km in 28:26, and halfway in 1:00:16 — quicker than the splits from Kiptum’s 2:00:35 world record in Chicago. For a while, it looked like history might be on.
But that sort of work rate just isn’t sustainable in less-than-ideal conditions. After 25–30 km, with the pacemakers gone and the sun heating up, the fade set in. By 35 km it was clear the record was gone. Sawe still broke the tape in 2:02:16, four minutes ahead of the next man, but what had been billed as a world record chase ended up being survival. His main rivals dropped out. Thousands of others who had come for PBs also found themselves cooking out there.
Not Just Berlin
It isn’t only Berlin that’s been caught out. London tipped over 20°C this April when it should’ve been in the low teens. Tokyo in March was hot and sunny. Chicago has had more warm Octobers than cool ones recently. Even New York, normally safe in November, hit 24°C in 2022 — its joint hottest ever.
Marathons are best in that 5–15°C window. Too warm, and the PB dream slips away. That’s why the records fall on the cool days — Kipchoge 2018, Assefa 2023, and now the men’s world record sitting with Chicago.
All Eyes on Chicago
The current world record is Chicago 2023: 2:00:35. That’s why attention is back there again this October. John Korir, the Boston winner, says he wants to go sub 2:01, Conner Mantz has the American record in his sights. Thousands more are heading to Chicago chasing their own breakthroughs.
The course can deliver. It’s flat, fast, and when the weather lines up, unbeatable. But last year ran hot and plenty of missed their goals. That’s the gamble with these big city majors now.
Backup Plans and Cooler Options
If you’re serious about a breakthrough you’ve invested a lot of time and effort to train yourself into the best marathon shape of your life, it’s smart to keep a backup race. Line up your A-race, then book in a second marathon 4–6 weeks later. If the weather doesn’t play ball, make the call to use the first race as tune-up/long run and then you’ve still got another shot to squeeze a big result out of that same training block.
Better chances for cool conditions:
- Valencia (December): consistently fast and near-perfect weather. Its the only non-major consistently dishing up the fastest times.
- Amsterdam (October): quick course, often cooler than Berlin.
- Frankfurt (late October): flat German roads, crisp autumn air.
- Seville (February): mild winter marathon.
- Rotterdam (April): cool spring, built for speed.
- Southern Hemisphere autumn: Ballarat! Some have even called it the Valencia of the South.
Berlin showed again that no course is immune. Sawe was on world record pace through halfway but the heat made sure it wasn’t to be. He still ran 2:02, but the chase was over long before the finish line.
And it leaves the bigger question hanging: is this going to become the norm for the majors — fast first halves, but heat turning the back half into damage control?