London Marathon 2025 Weather: Sunshine, Warm Temperatures, and Record-Breaking Crowds Expected
Bright Skies and Bustling Streets: What's in Store for 2025 London Marathon Participants?
The buzz around the London Marathon this year isn’t just about elite rivals, costumes, or crowd numbers—it’s about the weather. Forget the classic drizzle that’s soaked so many marathons in the past. This time, runners are in for a rare treat: actual sunshine. The Met Office says things will kick off with a crisp 10°C when runners lace up in the morning, but don’t expect that chill to last. As the race unfolds, the city will warm quickly, with temperatures climbing to a toasty 21–22°C by the time most cross the finish line. Some areas southeast of London might even nudge 24°C come Monday—practically a heatwave by April standards.
That’s a big change from the wet, unpredictable weather that’s hit the UK lately. April’s usually no stranger to showers, but recent rainfall has been below average. Met Office spokesperson Oli Claydon mentions this settled, dry spell feels especially welcome for marathoners used to bracing against wind and rain. Conditions this year should stay just right: no downpours, no strong winds, and not a cloud in sight by midday. The only thing runners might have to worry about is sunburn or overheating—a problem most will happily trade for soggy socks and puddles.
Massive Turnout and Marathon Milestones
The weather isn’t the only thing threatening records. With over 56,000 registered runners, this year’s event might steal the crown for the world’s biggest marathon finish from New York’s 2024 tally of 55,646. St James’s Park, Tower Bridge, and of course, Big Ben will set the stage for a truly epic crowd—whether you’re running, spectating, or just trying to get across town. The excitement goes beyond Sunday too: on Saturday, the streets will echo with the pounding feet of 17,000 kids taking on their own 2.6km Mini London Marathon.
When it comes to logistics, the race is a well-oiled machine. The wheelchair athletes launch proceedings bright and early at 8:50 AM. Top elite women follow at 9:05 AM, then it’s elite men at 9:35 AM. But the real tidal wave comes with the mass start, flowing out in waves between 9:35 AM and 11:30 AM. The course will wind through city sights soaked in sunshine, providing those perfect, Insta-worthy shots everyone hopes for.
For runners eyeing personal bests, conditions might feel almost dreamlike—though hydration will be crucial as the mercury rises. Training plans built for cool drizzle may need a last-minute adjustment, but for spectators and volunteers, the promise of blue skies is a definite win. After a string of gloomy, unsettled months, London pulling out all the stops with marathon-perfect weather feels more than a stroke of luck—it’s practically a victory for everyone involved.