2026 Chiba Aqua-Line Marathon - Nov 8

2026 Chiba Aqua-Line Marathon - Nov 8 Countdown

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Race Information

Race2026 Chiba Aqua-Line Marathon - Nov 8
CityKisarazu
Date2026-11-08 at 09:45
Field Size~12,000 runners
Time Limit6 hours 15 min
Cutoff pace8:53/km
TimezoneAsia/Tokyo
Official SiteChiba Aqua-Line Marathon Organizing Committee (ちばアクアラインマラソン実行委員会)

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Race Day Weather

Average Temperature14.5°C / 58°F
Humidity80%
Peak Wind18.9 km/h
Rain Chance36%
Typical ConditionsMild but breezy early-November conditions on Tokyo Bay, typically 13-18C at the 9:45 AM start, with a strong, exposed wind out over the open water of the Aqua Bridge.

What to Prepare: Dress for a mild start you can warm up in, but respect the wind on the bridge: a fitted layer beats anything that flaps, and a throwaway top for the corral keeps you warm before the 9:45 gun.

Based on historical averages for race week. Use our Weather Score Calculator and What to Wear Guide for personalized advice.

Wind Impact on Race Day

Winds peaking around 18.9 km/h — the typical daily maximum for this date — can affect your pace by 5-15 seconds per kilometer in exposed stretches. Headwinds slow you down exponentially: a 20 km/h wind costs more than twice a 10 km/h wind.

Calculate your wind-adjusted pace →

Race-Week Climate

Based on 20 years of race-week weather (2005-2024), MERRA-2 reanalysis

Cooler Typical Warmer
Temperature 11.5°C 14.6°C 17.6°C
Dew point 6.6°C 10.8°C 15.2°C
Wet-day chance: 36% Runnability: 74/100

Data: NASA POWER (MERRA-2 reanalysis), NASA Langley Research Center

Course Profile

Course TypeOut-and-back road marathon over an expressway bridge
Elevation Gain280m
TerrainRoad (expressway bridge and city streets)
ProfileA genuinely tough rolling course: surface roads through Kisarazu lead onto the Tokyo Bay Aqua-Line, where you climb the Aqua Bridge to roughly 40 m above the sea toward the Umihotaru turnaround, with the official profile putting the late high points at 34.3 km (40.6 m) and 38.2 km (35.8 m).

Prepare for 2026 Chiba Aqua-Line Marathon - Nov 8

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Frequently Asked Questions

When and where is the Chiba Aqua-Line Marathon 2026?

The Chiba Aqua-Line Marathon 2026 is held on Sunday, November 8, 2026, with a 9:45 AM gun start. The full marathon starts in Kisarazu City on Tokyo Bay, runs out onto the Tokyo Bay Aqua-Line expressway, and turns around near Umihotaru, the man-made island rest stop in the middle of the bay, before returning through the city.

Why is this race held only every two years?

The Aqua-Line is a working expressway and one of the busiest crossings of Tokyo Bay, so fully closing it for a marathon is a major undertaking that the organizers stage only once every two years (even-numbered years since 2012). The 2026 edition is the 7th running. If you miss it, the next opportunity will not come until 2028, which makes planning ahead well worth it.

How do I enter, and is there a lottery?

From the 2026 edition the marathon switched to first-come, first-served entry rather than the lottery used in past years, and all 11 entry frames have since closed. The general frame opened at 8 PM on March 22, 2026 and hit its quota the next day; a late-entry frame opened on May 31 and filled the same evening. The full-marathon entry fee was 16,500 yen, and the next edition is 2028. Use our race time predictor to set a realistic goal before you commit.

Is the course flat and fast, or is it a hard race?

It is a hard one. Despite the smooth expressway surface, this is not a personal-best course: there are several climbs of more than 35 m, including the long pull up onto the Aqua Bridge, and the official course profile puts the late high points at 34.3 km and 38.2 km, with the organisers singling out the hills from just past 33 km. Add an exposed sea wind over the open water and you should pace conservatively. Map your effort with our pace calculator.

What is the time limit?

The marathon course closes at 4:00 PM, which is 6 hours 15 minutes for the 9:45 AM first wave and less for the 9:50 and 9:55 waves, since official times run from your own wave gun. Nine checkpoints close along the route, and the start line itself shuts at 10:10 AM. That is tighter than some Japanese city marathons, and with the bridge climbs and wind it suits experienced finishers more than first-timers. If you are chasing the cutoff, bank time early on the flatter city sections.

Can I use my time for Boston qualifying?

No. The Aqua-Line course is not JAAF (日本陸連) certified because the over-water expressway route cannot meet certification rules, so your time here cannot be used for a Boston qualifier. Treat this as a bucket-list experience rather than a qualifying attempt, and chase your BQ at a certified flat course instead. Check your standard with our Boston qualifying calculator.

How do overseas runners get there, and is a visa needed?

Many nationalities can enter Japan visa-free for short tourist stays; confirm your own country's rule before booking, and note Japan currently has no ESTA-style pre-authorization. Kisarazu sits across Tokyo Bay from central Tokyo and is reachable by highway bus over the Aqua-Line in roughly an hour, making a race trip from the capital straightforward.

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