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MarathonPlanning ahead

2027 RACE BRIEFING

Tokyo Marathon

Tokyo, Japan
GOAL FINISH Edit ↗3:15:00
WEATHER SNAPSHOT3:15:00

+0:00 versus your goal from a single 09:00 five-year ERA5 calendar-window mean snapshot.

Prepare for the Tokyo Marathon with March climate context, official race information and an even-pace reference for your goal time.

Explore your pace plan
THE COURSE42.2 km
Know the streets before the gun.

The official route runs from the Tokyo Metropolitan Government Building to Tokyo Station via central Tokyo. Course geometry is not available in this guide; use the organiser's map.

See organiser route details
See the organiser for the current route
01 / THE CONDITIONS

Race-day weather

158 days to race day

Good preparation starts before the forecast.

Race-day forecasts appear here within 15 days of the event, when data is available. Until then, explore the course and historical weather below.

Explore historical weather
02 / SAME EFFORT, DIFFERENT DAY

What the weather may cost

Historical planning snapshot

RunWeather’s shared pace model estimates the effect of one weather hour at your goal effort. It is a planning preview, not a predicted finish time or a full course simulation.

Thermal load0%Heat, cold and sun
Wind & comfort0%City-point wind; no route exposure
Weather model total0%Applied to the goal-time snapshot above

Snapshot at 09:00 local using five-year ERA5 calendar-window mean. Route climbing, turns, shelter, fuelling, fitness, heat adaptation and wave timing are not modelled here. Rain is excluded because a probability is not a measured rain rate. Explore the pace model.

03 / KNOW THE ROUTE

What the course asks of you

Official race site

The official route runs from the Tokyo Metropolitan Government Building to Tokyo Station via central Tokyo. Course geometry is not available in this guide; use the organiser's map.

01

Confirm your assigned start time in the event instructions when the race approaches.

02

Plan a warm layer for the start wait separately from the kit you intend to race in.

03

Check the final forecast during race week; a March average cannot predict race-day conditions.

04 / THE RACE WINDOW

What mornings like this have looked like

ERA5 historical sample

A useful range for planning Tokyo Marathon: hourly weather near Tokyo for the same calendar date ±5 days in 2021–2025. These are city-grid samples, not past race editions or a forecast.

Typical start-hour air8°C10th–90th percentile 5°C–13°C
Dew point / humidity1°C64% relative humidity
Start-hour wind12 km/hDirection varies by day
Hours with rain13%Historical frequency at this hour
AIR THROUGH THE RUN

The five-year picture

8°C → 12°C by +4h
09:00
Air temperature
8°C
Humidity
64%
Wind
12 km/h
Hours with rain
13%
3°C9°C15°C21°CStartGoal finish09:0011:0013:0015:00

Hover or drag to explore. Use ← → when focused. Shading: middle 80% of sampled temperatures.

Five-year average Middle 80% of sampled hours

The sampled air warms by about 4°C across four hours. Check your expected finish-hour forecast, not just the start.

WIND CONTEXT

Where the breeze came from

NN: 20 of 55 sampled start hours; mean 11 km/hNENE: 8 of 55 sampled start hours; mean 11 km/hEE: 5 of 55 sampled start hours; mean 7 km/hSESE: 5 of 55 sampled start hours; mean 3 km/hSS: 1 of 55 sampled start hours; mean 31 km/hSWSW: 3 of 55 sampled start hours; mean 12 km/hWW: 1 of 55 sampled start hours; mean 2 km/hNWNW: 12 of 55 sampled start hours; mean 18 km/h
WIND FROMN

20 of 55 samples · 36%
Mean 11 km/h

The petals show how often the wind came from each direction at the sampled start hour. They do not predict the direction on race day.

A city-point wind rose cannot tell you which parts of the course will be sheltered or exposed. Use the live forecast and the organiser’s route map together.

Method: 55 ERA5 hourly samples at 09:00 local time, across 11 calendar days per year in 2021–2025. A 09:00 sample is used because the organiser has not confirmed a first start in this guide. Grid weather is modelled reanalysis, not an on-course station reading. Open-Meteo Historical Weather API . Snapshot generated 2026-09-29.

05 / THE BIGGER PICTURE

March conditions across all hours

Historical climate

March averages in Tokyo, based on 2022–2024 ERA5 history. These are monthly conditions, not a race-day forecast.

Mean temperature10°C
Mean humidity68%
Mean wind17 km/h
Hours with rain18%

Monthly, all-hours averages for Tokyo, 2022–2024. Not past race-day measurements or a forecast. Rain is the share of historical hours with precipitation, not the chance of rain on race day. Source: Open-Meteo ERA5.

Explore running weather in Tokyo
06 / MAKE A PLAN

Find your starting pace

Start with your goal. Leave room for the day.

Set a finish time to compare an even-pace baseline with a one-hour weather snapshot. Use the changing forecast and course notes to decide where to be more conservative.

Goal finish time

Choose a popular time or set your own. Your pace and weather preview update as you edit.

The baseline ignores hills and stops. The weather preview models one selected hour.

Explore the heat pace calculator
YOUR GOAL PACE
4:37/km

3:15:00 finish · 42.2 km

Same-effort weather snapshot3:15:00+0:00 at 09:00 · historical window
View even-pace checkpoints
DistanceElapsed time
5.0 km0:23:06
10.0 km0:46:13
15.0 km1:09:19
20.0 km1:32:26
25.0 km1:55:32
30.0 km2:18:39
35.0 km2:41:45
40.0 km3:04:51
42.2 km · Finish3:15:00
07 / BEFORE THE START

Tokyo Marathon FAQs

When is the 2027 Tokyo Marathon?

Tokyo Marathon is scheduled for 7 March 2027. Confirm the latest details on the official event website before travelling.

Is the weather shown a forecast for Tokyo Marathon?

The race-day forecast panel uses provider data for the event date when available. The 2021–2025 ERA5 race-window sample describes nearby calendar dates, not held race editions or a prediction for race day. Monthly averages, when shown, cover all hours of the event month.

What is the historical race-window weather like for Tokyo Marathon?

At 09:00 local, the 2021–2025 ERA5 calendar-window sample near Tokyo averages 8°C, 64% relative humidity and 12 km/h wind. The middle 80% of sampled start-hour temperatures is about 5–13°C. These are 55 city-grid samples from the event date ±5 days, not observations from held editions or a forecast.

Can the race-window history predict Tokyo Marathon weather?

No. It describes the same calendar window in 2021–2025. Use the live event-day forecast when available, check conditions through your own expected finish time, and follow the organiser for current start and course information.

Sources & race information

Weather-window data: Open-Meteo ERA5 Historical Weather API, sampled at the city grid for 2021–2025 and generated 2026-09-29. These calendar-window samples are not official race-day observations.

Guide reviewed . RunWeather is an independent guide, not the race organiser. Dates, waves and routes can change; the organiser’s latest instructions take priority.

ANOTHER START LINE

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YOUR NEXT STEP

A race plan that goes with you.

Explore race planning and running forecasts in RunWeather. Keep your training and race-day preparation together.

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Tokyo Marathon 2027: Weather & Pacing Guide | RunWeather