2027 Three Forts Marathon - May 2 Countdown

Q: What is the Three Forts Marathon route?

The Three Forts Marathon starts and finishes at Lancing Manor Leisure Centre in West Sussex and runs an off-road loop over the South Downs above Worthing, climbing over three Iron-Age hill forts: Cissbury Ring, Chanctonbury Ring and the Devil's Dyke area. The course follows chalk tracks, open grass downland, the South Downs Way and public bridleways with stiles, crossing the River Adur valley along the way. It has run since 1977 and is known affectionately as The Tough One.

Q: How long is the Three Forts Marathon - is it really 27 miles?

Yes. The full Three Forts Marathon is approximately 27.2 miles, around a mile longer than a standard 26.2-mile marathon. The extra distance comes from the off-road route linking the three hill forts across the Downs. There is also a half marathon and a 5-mile trail run on the same day if the full distance is not for you. Plan a realistic finish time with our finish time calculator, remembering the extra mile and the climbs.

Q: Is the Three Forts Marathon flat? How hard is it?

It is not flat - it is one of the toughest marathons in southern England, which is exactly why it is nicknamed The Tough One. The course packs in around 3,450ft (about 1,050m) of climb over open chalk downland, with stiles and rough tracks underfoot. Combined with the extra mile of distance, most runners finish well outside their road-marathon time. Map your effort with our pace calculator and study the climbs with our elevation profile tool.

Q: What surface is it and what shoes should I wear?

The course is almost entirely off-road on chalk tracks, open grass and rough public bridleway, with several stiles to climb. It is not a road race. Trail or off-road shoes are strongly recommended for grip, especially as chalk and grass turn slippery in the wet. In a dry early-May spell road trainers can cope, but most runners are more comfortable and confident in trail shoes on the descents.

Q: How do I enter the Three Forts Marathon 2027, and what does it cost?

Entry is open to the public online through the official Three Forts Challenge site (threefortschallenge.org.uk), with no ballot. The 2026 marathon fee was around 49 GBP; 2027 pricing is confirmed nearer the event. It is a popular community race that can fill, so book ahead. Net proceeds support Ferring Country Centre and local Sussex charities.

Q: What time does it start and what is the cut-off?

The marathon starts at 09:00 from Lancing Manor Leisure Centre on Sunday 2 May 2027, with registration open from 8am. There is a 6-hour overall time limit, after which aid stations gradually close, so you need to average comfortably inside that to finish supported. The half marathon and 5-mile run start the same morning.

Q: Is the Three Forts Marathon a Boston Qualifier?

No. Because it is an off-road South Downs trail course of about 27.2 miles rather than a UK Athletics road-certified, accurately measured 26.2-mile race, a Three Forts finish is not valid for Boston qualifying (BQ) or a London Good For Age (GFA) entry. Come for the scenery, the hills and the challenge, not a PB. If a qualifying time is your goal, check the standards with our Good For Age tool and choose a fast, flat road race instead.

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Race Information

Race	2027 Three Forts Marathon - May 2
City	Lancing
Date	2027-05-02 at 09:00
Time Limit	6 hours
Cutoff pace	8:32/km
Timezone	Europe/London
Official Site	Rotary Clubs of Worthing & local running clubs
Registration	Register · 49 GBP

Race Day Weather

Average Temperature	10.6°C / 51°F
Humidity	82%
Wind	23.3 km/h
Rain Chance	36%
Typical Conditions	A bright but breezy spring morning on the exposed South Downs above Worthing. Expect around 10-11C (50-52F) at the 09:00 start, climbing into the mid-teens by midday, with high humidity and a steady coastal wind funnelling over the open ridgeline. Late-spring sun can feel strong once you are up on the chalk with no shade.

What to Prepare: Dress for cool double-digit Celsius at the start with a layer you can stuff away as you warm up on the climbs. There is almost no shade on the Downs, so carry sun protection and your own fluids between aid stations. Wear trail or off-road shoes for grip on chalk, grass and rough bridleway, and pace by effort, not by your flat road time.

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

Wind at 23.3 km/h can affect your marathon pace by 5-15 seconds per kilometer. 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	7.7°C	10.6°C	13.3°C
Dew point	3.9°C	7.8°C	10.7°C

Wet-day chance: 36% Runnability: 71/100

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

Course Profile

Course Type	Off-road loop over the South Downs, start and finish at Lancing Manor Leisure Centre
Elevation Gain	1050m
Terrain	Trail
Profile	A genuinely hard, hilly off-road course of roughly 27.2 miles - about a mile longer than a standard marathon - with around 3,450ft (1,050m) of total climb. The route crosses three Iron-Age hill forts, Cissbury Ring, Chanctonbury Ring and the Devil's Dyke area, over chalk tracks, grass and rough bridleway with stiles. Expect to finish well outside your road-marathon time.

Prepare for 2027 Three Forts Marathon - May 2

Use our free training tools to get race-ready:

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Dew Point Running Calculator — Pace Adjustment Chart

Enter temperature and humidity to calculate dew point and its impact on your running pace. 7-zone ch...

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Wind Effect on Running — How Much Does Wind Slow You?

How much does a headwind actually slow you down? This free calculator turns wind speed and direction...

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Elevation Gain/Loss Impact Calculator

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Frequently Asked Questions

What is the Three Forts Marathon route?

The Three Forts Marathon starts and finishes at Lancing Manor Leisure Centre in West Sussex and runs an off-road loop over the South Downs above Worthing, climbing over three Iron-Age hill forts: Cissbury Ring, Chanctonbury Ring and the Devil's Dyke area. The course follows chalk tracks, open grass downland, the South Downs Way and public bridleways with stiles, crossing the River Adur valley along the way. It has run since 1977 and is known affectionately as The Tough One.

How long is the Three Forts Marathon - is it really 27 miles?

Yes. The full Three Forts Marathon is approximately 27.2 miles, around a mile longer than a standard 26.2-mile marathon. The extra distance comes from the off-road route linking the three hill forts across the Downs. There is also a half marathon and a 5-mile trail run on the same day if the full distance is not for you. Plan a realistic finish time with our finish time calculator, remembering the extra mile and the climbs.

Is the Three Forts Marathon flat? How hard is it?

It is not flat - it is one of the toughest marathons in southern England, which is exactly why it is nicknamed The Tough One. The course packs in around 3,450ft (about 1,050m) of climb over open chalk downland, with stiles and rough tracks underfoot. Combined with the extra mile of distance, most runners finish well outside their road-marathon time. Map your effort with our pace calculator and study the climbs with our elevation profile tool.

What surface is it and what shoes should I wear?

The course is almost entirely off-road on chalk tracks, open grass and rough public bridleway, with several stiles to climb. It is not a road race. Trail or off-road shoes are strongly recommended for grip, especially as chalk and grass turn slippery in the wet. In a dry early-May spell road trainers can cope, but most runners are more comfortable and confident in trail shoes on the descents.

How do I enter the Three Forts Marathon 2027, and what does it cost?

Entry is open to the public online through the official Three Forts Challenge site (threefortschallenge.org.uk), with no ballot. The 2026 marathon fee was around 49 GBP; 2027 pricing is confirmed nearer the event. It is a popular community race that can fill, so book ahead. Net proceeds support Ferring Country Centre and local Sussex charities.

What time does it start and what is the cut-off?

The marathon starts at 09:00 from Lancing Manor Leisure Centre on Sunday 2 May 2027, with registration open from 8am. There is a 6-hour overall time limit, after which aid stations gradually close, so you need to average comfortably inside that to finish supported. The half marathon and 5-mile run start the same morning.

Is the Three Forts Marathon a Boston Qualifier?

No. Because it is an off-road South Downs trail course of about 27.2 miles rather than a UK Athletics road-certified, accurately measured 26.2-mile race, a Three Forts finish is not valid for Boston qualifying (BQ) or a London Good For Age (GFA) entry. Come for the scenery, the hills and the challenge, not a PB. If a qualifying time is your goal, check the standards with our Good For Age tool and choose a fast, flat road race instead.

How do I get to the start, and where do I stay?

Lancing Manor Leisure Centre sits just inland of the coast in West Sussex, between Worthing and Brighton. Lancing railway station is a short distance away on the London Victoria to Southampton line, and there is on-site parking for those driving. Worthing, Lancing and Shoreham-by-Sea offer plenty of seafront hotels and guesthouses within a few miles, and Brighton is a short train ride east for a wider choice and a livelier base.