
Eureka, United States of America · Sunday 9 August 2026
Held in August in Eureka, the Humboldt Bay Marathon offers a flat to gently rolling course that won't punish your legs with climbing, making it a solid choice if you're chasing a time or testing fitness without major elevation battles. The course stays low overall, ranging between sea level and just above 50 meters, so what you see is what you get in terms of effort. August in coastal Northern California means you should prepare for variable weather, potentially cool and damp conditions typical of the region. The race is road-based, so you'll be on pavement the whole way, which is good for your pace but worth noting if you prefer trail variety. Check the official race website closer to 2026 for start time, course specifics, and entry details, since logistics for a relatively smaller marathon can vary year to year.
Adjusted Time
3:52:32
Time difference: -7.5 minutes compared to a flat, road, temperate course.
Humboldt Bay Marathon is a full marathon held in Eureka, United States of America, scheduled for Sunday 9 August 2026. The course is run on road surface with 0m of total elevation gain, reaching a maximum altitude of 51m above sea level.
This is a very flat course with only 0m of total elevation gain across the full distance. The course ranges from 1m to 51m above sea level — a 50m elevation range that makes it one of the flatter races available. Runners targeting a personal best will appreciate the minimal climbing.
Humboldt Bay Marathon is run on road surfaces, which provide the fastest and most predictable conditions for marathon running. Road courses allow for consistent pacing and are typically the best choice for runners targeting a personal best time.
Our difficulty rating for Humboldt Bay Marathon is calculated using a model that combines elevation gain, temperature impact, and surface type. Use the difficulty calculator above to enter your target finish time and see exactly how many minutes this course would add or subtract compared to a perfectly flat, cool, road-based marathon. Faster runners and slower runners are affected differently by the same course conditions, so the difficulty is personalised to your pace.
Looking for an easier marathon or a tougher challenge? You can also compare Humboldt Bay Marathon against other marathons to find the right race for your goals.
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