Escape into the vast, tranquil wilderness of Northumberland for the Altra Kielder Marathon Weekend, October 3-4, 2026, where the celebrated "Britain's most beautiful" marathon unfolds around the stunning shores of Northern Europe's largest man-made lake. This iconic weekend offers a challenge for every athlete, from the flagship off-road marathon and half marathon to a fast 10k, a thrilling Gravel Duathlon, and inclusive junior races, all set within the breathtaking Kielder Water & Forest Park. The marathon course is a uniquely serene and demanding 26.2-mile trail journey, where runners are immersed in pristine pine forests and treated to sweeping, uninterrupted views of the iconic landscape with every step. Organized by Events of the North, the weekend is renowned for its impeccable, friendly atmosphere and deep connection to the natural environment, creating a perfect balance of peaceful solitude and shared community spirit. Whether you're a seasoned trail runner seeking a pristine, traffic-free route or a road athlete looking for a scenic new challenge, Kielder provides an unforgettable backdrop for personal achievement. Secure your entry for an autumn weekend where the only sounds are your footsteps on the trail and the collective celebration at the finish line, all within one of the UK's most majestic and unspoiled settings.
Races Offered
10 KM
Oct 03, 2026
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Distance —
10K
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Type —
Multisports
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90 days remaining
Run Bike Run
Oct 03, 2026
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Distance —
11K 25K 6K
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Type —
Multisports
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90 days remaining
Half Marathon
Oct 04, 2026
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Distance —
21.1K
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Type —
Multisports
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90 days remaining
Marathon
Oct 04, 2026
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Distance —
42.2K
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Type —
Multisports
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90 days remaining
Weather History
These values represent the 3-year monthly averages for October in Kielder.
thermostatTemperature
6.8° / 11.7°
wb_sunnyFeels like
3.0° / 8.0°
light_mode
Avg sunshine hours
4h 37m
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Avg rainfall
4.3 mm
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Avg snowfall
—
air
Avg wind speed
16.6 km/h (Gentle breeze)
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Sweat loss rate
Low
terrain
Course conditions
Firm and slightly soft
sunny
Max UV Index
Low (2.8)
humidity_mid
Humidity
90.7%
wb_twilight
Sunrise
07:42
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Sunset
18:08
About Kielder
Learn more about the host city, Kielder.
Kielder is a small, remote village in western Northumberland, England. Located at the head of Kielder Water and in the north west of Kielder Forest, the village is within three miles of the Scottish border.
