London · Sun, April 25, 2027 · 09:30
Prime BQ course · forgiving course · very high friction
Boston-qualifying course; see the BQ Finder for the effective application effect.
Flat, cool race morning.
Lottery (~4% accepted) · ~$2,065 all-in from South Florida.
Date verified at the official source; course and climate data on file.
Legacy Green Score 7.4/10 · method
At the start line and start hour · NOAA 1991–2020 climate normals
Projected at race day for M 18-34, from your 4:00:00 marathon + training runway.
Registration / lottery closes Sun, May 3, 2026
World Major. Lottery ~4%. Flat. International travel from Miami.
The TCS London Marathon is a marathon held in London on April 25, 2027. With a Green Score of 7.4/10, it's a moderate race. The course is flat (~9 ft of gain per mile). Typical race-day weather is a cool 48°F, dew point ~40°F (10-year normal). It is a Boston-qualifying course. Entry is around $175. Marathon Compass rates every race across terrain, climate, logistics, travel, and field size so you can find the one that fits you — and build a training plan tuned to your fitness.
Typical start-line conditions (30-year normal (NOAA 1991–2020)): 48°F with a dew point of 40°F. On the temperature-plus-dew-point scale used by our pace engine, that's 88 — a 0% pace penalty. Heat should not be a factor at the TCS London Marathon in a typical year — race your fitness.
Method: temp°F + dew°F lookup from the heat-adjustment chart our training plans use daily. Sign in to see this adjustment applied to your own projected finish.
First marathons cost more than the entry fee — budget the whole weekend before you commit.
Net descent of ~0 ft is well under the BAA's 1,500 ft adjustment threshold. Your clock time is your application time.
Computed under the BAA's downhill rules for the 2027 qualifying window (announced Sept 2025; verified July 2026): net start-to-finish descent of 1,500–2,999 ft adds 5:00, 3,000–5,999 ft adds 10:00, and 6,000 ft or more is not accepted. Net descent here is derived from our course elevation data — the BAA's official course designation controls. Sign in to see your projected finish graded against your age-group standard and the realistic acceptance cutoff.
Entry is by lottery with roughly 4% historical acceptance — plan like you might not get in.
Plan B: if entry doesn't go your way, Shamrock Marathon Virginia Beach (March 21, 2027, open entry, Green Score 9.2) or A1A Marathon (Fort Lauderdale) (February 14, 2027, open entry, Green Score 8.6) keeps the same training block on schedule.
Point-to-point course: stay near the finish, not the start — you'll be glad at mile 26, and shuttles run to the start. Hotels near the TCS London Marathon start selling out 8–10 months ahead with race-weekend minimum stays — book refundable, book early. The links below are pre-filled for race weekend (April 23, 2027 → April 26, 2027).
When to wake up, when the corral closes, and the exact clock time TCS London Marathon spectators should be at each split for your goal pace — plus a link you can send to whoever's coming to watch.
Build your race-day timeline →Race and date verified against the official race source on 2026-07-17. 2027 is a one-off two-day 'Double' (Apr 24–25); we list the Sunday. Race-morning climate from Open-Meteo — 10-year history at the start line and start hour. Race fees, dates, and rules change often — report incorrect information.