Running · London, GB
Edition
2027
Two days, one Greenwich-to-Westminster route, and a course page that is not stamped 2027.
Race day
April 24, 2027
Distance
Marathon
Climbing
125 m
Photo: p_a_h (via Wikimedia Commons) · CC BY 2.0
2026 operating status
Know what is final.
Saturday 24 and Sunday 25 April 2027. 100,000 runners. First two-day edition, and the homepage says it is the only time.
SourceDouble FAQ: Saturday likely 09:00, finish close 17:30, which it calls 7 hours 45 minutes. Sunday likely 09:30. To be confirmed to participants.
SourceThe course page has no GPX. It is not labeled 2027. Both days use the Greenwich to Westminster route, per the double FAQ.
SourceRace weekend board
Every race weekend has a different failure point. Tell us who is coming and what the hotel must solve; the board changes the base, spectator plan, and race-day timing.
Your strongest base
Greenwich ParkWhy this result · This base matches “I’m racing” and “Start logistics” more strongly than the other authored options.
The course page titles the route from Greenwich to The Mall, with three starts that meet just before mile 3 in Woolwich. This pin is Greenwich Park, not one of those start lines.
Tradeoff: Useful if your start is on this side of the city. Wrong for The Mall.
Course timing signal
Greenwich address, start side.
Accor prints 173-185 Greenwich High Road, London SE10 8JA, and a geo position of 51.477798, -0.013504.
Consider: Three starts meet in Woolwich, not at this door. It is not a Mall hotel.
Address and geo position from the Accor hotel page, opened 4 November 2026.
03 / Predicted finish
These are elapsed estimates after the runner crosses the start, not clock times. Add transit and security margin.
Give this to your support crew
Miles are the undated course page. The page does not say 2027.
Cutty Sark
The course page does not name a station.
The page says the route loops around Cutty Sark between miles 6 and 7.
Rainbow Row, Limehouse
The course page does not name a station.
A 250-metre stretch just past mile 21, on that page.
Meetup: Tower Bridge is the loud part the page describes, and it does not give the bridge its own mile.
Compare the tradeoffs
Saved on this device
London splits 2027 across 24 and 25 April, with 100,000 runners and the day fixed on the entry. Saturday's finish closes at 17:30. Sunday's start is printed as likely 09:30, and the FAQ says the clocks will be confirmed later. The course page has the miles and no GPX. Book the day you were given, not the other one.
The homepage and the double FAQ, opened 4 November 2026, put the race on Saturday 24 and Sunday 25 April 2027, with 100,000 runners. Saturday is likely to start at 09:00 and the finish closes at 17:30. Sunday is likely to start at 09:30. The FAQ says those clocks will be confirmed later. The course page describes the route and does not say 2027. It has no GPX.
The course page, opened 4 November 2026 and not stamped 2027, describes three starts that meet just before mile 3 in Woolwich, Cutty Sark between miles 6 and 7, Tower Bridge toward halfway, The Highway after 13 miles, Rainbow Row just past mile 21, and a finish on The Mall. The double FAQ says both 2027 days use the Greenwich to Westminster route. No GPX was linked. The 125 m and 54 m figures already stored here were not on that page.
Difficulty is the course and the conditions. The PR score is a separate read on a fast clock. Missing inputs are dropped and the other weights are rescaled. The method, with the weights.
Weight used: 60%. Need 40% before we print a number.
Weight used: 30%. Need 45% before we print a number.
Weather median for 2011–2025, race date ±7 days, 225 days, at Greenwich Park (park pin, not a start line). Grid elevation 47 m.
No cited BQ rate for this race.
| Input | 0–100 | What went in |
|---|---|---|
| G Gain | — | No trusted gain per km. Uncertain stored gain is not used. |
| A Altitude | 0 | 47 m. 0 below 300 m, 100 at 2000 m. Source: open-meteo-grid. |
| H Heat | 30 | High 14.3°C, dew point 4.9°C. The hotter of the two bands is used. |
| W Wind | 40 | 3.63 m/s median. Bands: under 3 → 15, under 5 → 40, under 8 → 70, else 100. |
| S Surface | 15 | road. Road 15, mixed 45, gravel 70, trail 90. |
| T Cool temps | 70 | 100 minus heat (30). |
| B BQ evidence | — | No cited BQ rate. |
Four-day operating plan
Friday 23 April 2027
01Saturday 24 April 2027
02Sunday 25 April 2027
03
Difficulty 22
Difficulty 22 · PR 83
Difficulty 32 · PR 33
Difficulty 54