Best Weather Marathons: A Data-Driven Ranking

You can train perfectly for 16 weeks and still have your marathon ruined by weather. Temperature, wind, humidity, and precipitation collectively account for a larger share of marathon performance variance than almost any other external factor — yet most runners choose their race based on location, prestige, or convenience, not climate.

At Havik, we model weather conditions for every race in our database using historical data, forecast APIs, and course-specific wind analysis. To help runners make smarter race choices, we ranked 10 of the world’s most popular marathons by weather friendliness using five key metrics: average temperature, temperature variance, wind speed, precipitation probability, and humidity.

The methodology is simple: we scored each marathon on a 0–100 scale for each metric (100 = ideal for performance), then calculated a weighted composite. Temperature carries the heaviest weight (35%), followed by wind (25%), temperature variance (20%), precipitation (10%), and humidity (10%).

The Ranking: 10 Major Marathons by Weather Friendliness

1. Berlin Marathon (late September)

Composite score: 92/100. Berlin is the gold standard for marathon weather. Average race-day temperature is 12°C (54°F) with a standard deviation of just 2.8°C. Sustained wind averages 8 km/h on the flat, loop course. Precipitation probability is 20%, and humidity typically sits at 55–65%. It is no coincidence that Berlin has produced more marathon world records than any other course — the weather is a major reason.

2. London Marathon (late April)

Composite score: 87/100. London benefits from the Gulf Stream’s moderating influence. Average race-day temperature is 11°C (52°F) with a standard deviation of 3.1°C. Wind averages 12 km/h, and the loop course means headwinds and tailwinds tend to cancel. Precipitation probability is 30%, slightly higher than Berlin, but rain in London is typically light and intermittent rather than sustained.

3. Chicago Marathon (early October)

Composite score: 85/100. Chicago’s early October date hits the autumn sweet spot. Average race-day temperature is 13°C (55°F) with a standard deviation of 3.4°C. Wind averages 14 km/h — the lakefront segments can produce gusty crosswinds, but the urban canyons provide shelter on most of the course. Precipitation probability is 22%. Chicago’s main risk is the occasional warm outlier year (2007 reached 31°C, forcing a race cancellation).

4. Valencia Marathon (early December)

Composite score: 84/100. Valencia has emerged as one of Europe’s fastest marathons, and weather is a big reason. The early December date delivers average temperatures of 12°C (54°F) with remarkably low variance (standard deviation 2.5°C). Wind averages just 7 km/h on the flat coastal course. Precipitation probability is 15%. The one downside: humidity can reach 70–80% due to Mediterranean proximity.

5. Tokyo Marathon (early March)

Composite score: 81/100. Tokyo’s early March date typically delivers cool, dry conditions. Average race-day temperature is 9°C (48°F) with a standard deviation of 3.2°C. Wind averages 11 km/h. Precipitation probability is 25%. The urban course offers significant wind shelter from Tokyo’s skyscrapers. The main risk is a late-season cold snap that can push temperatures below 5°C.

6. New York City Marathon (early November)

Composite score: 78/100. New York’s early November date offers good temperature conditions — average 11°C (52°F) with a standard deviation of 3.6°C. However, the five-borough course crosses exposed bridges (Verrazzano-Narrows, Queensboro, Willis Avenue) where wind speeds can spike to 30–40 km/h. Average sustained wind is 16 km/h. Precipitation probability is 20%. The Verrazzano crossing in the first 3 km is a notorious energy trap on windy years.

7. Amsterdam Marathon (mid-October)

Composite score: 76/100. Amsterdam offers a fast, flat course with good autumn temperatures averaging 11°C (52°F) and a standard deviation of 3.0°C. The main downside is wind: the Netherlands is notoriously windy, and exposed sections along canals and through Amstelveen average 18 km/h sustained. Precipitation probability is 35% — the highest on this list alongside Boston. Humidity sits at 75–85%.

8. Marine Corps Marathon (late October)

Composite score: 74/100. The Marine Corps Marathon in Washington, D.C. offers average temperatures of 14°C (57°F) with a standard deviation of 4.0°C. Wind averages 12 km/h, and the Potomac River sections can funnel gusts. Precipitation probability is 25%. D.C.’s proximity to the Mid-Atlantic weather systems means conditions can shift rapidly; warm outlier years (18–22°C) are not uncommon.

9. Boston Marathon (mid-April)

Composite score: 65/100. Boston is one of the most prestigious marathons in the world, but its weather is among the least predictable. Average race-day temperature is 13°C (55°F), but the standard deviation of 4.7°C is the highest on this list. The 10-year range spans 3°C to 21°C. Sustained wind averages 16 km/h, predominantly headwind on the point-to-point course. Precipitation probability is 30%. For a deeper dive, see our Boston Marathon weather analysis.

10. Houston Marathon (mid-January)

Composite score: 62/100. Houston’s mid-January date is designed to dodge the Texas heat, and it mostly succeeds: average race-day temperature is 11°C (52°F). However, Houston weather is volatile. The standard deviation is 5.1°C — the highest of any major marathon. Some years see 5°C at the start; others start at 20°C with 80%+ humidity. Wind averages 14 km/h. Precipitation probability is 28%. The humidity (often 70–90%) is the real performance killer.

Weather Comparison at a Glance

What Makes Marathon Weather “Good”?

Performance-optimal marathon weather is defined by four conditions working together:

• Temperature: 7–15°C (45–59°F). This range minimizes thermoregulatory load. The body generates approximately 1,000 watts of metabolic heat at marathon pace; cool air dissipates it efficiently without the cardiovascular cost of heavy sweating.
• Wind: below 15 km/h sustained. Aerodynamic drag increases with the square of wind speed. A 10 km/h headwind adds roughly 3–5 seconds per kilometer; a 20 km/h headwind adds 6–10 seconds. For a full breakdown, see our wind and marathon pace guide.
• Precipitation: none or light drizzle. Heavy rain adds weight (wet clothing can add 0.5–1.0 kg), increases blister risk, and combined with wind causes rapid heat loss. Light drizzle in cool conditions can actually be beneficial for evaporative cooling.
• Humidity: 40–60%. Low humidity allows efficient sweat evaporation. Above 70%, the body’s primary cooling mechanism becomes impaired, and effective temperature rises significantly above what the thermometer reads.

Why Weather Variance Matters More Than Averages

A marathon with a 12°C average but a 5°C standard deviation is a fundamentally different proposition than one with a 12°C average and a 2°C standard deviation. The high-variance race might give you a perfect 10°C day — or it might give you 22°C and 80% humidity.

This is why Berlin and Valencia consistently produce fast times: not only are their averages near-ideal, but their conditions are predictably near-ideal. When you register for Berlin eight months in advance, you can be reasonably confident that race-day temperature will fall between 9°C and 15°C. With Boston, you might get anything from 3°C to 21°C.

For runners chasing a BQ, a PR, or a specific time-based goal, choosing a low-variance marathon reduces the probability that weather becomes the deciding factor. You cannot control the weather, but you can choose a race where the weather is more likely to cooperate.

How to Use This Data for Race Selection

• Chasing a BQ or PR? Prioritize marathons in the top 5. Berlin, Valencia, and Chicago offer the best combination of fast courses and favorable weather. The difference between racing in ideal vs. marginal conditions can be 5–15 minutes for a 3:30 marathoner.
• Heat-sensitive runner? Avoid races ranked below #7 or any race with average temperatures above 14°C. Consider Tokyo or London for reliably cool conditions.
• Wind-sensitive runner? Valencia (7 km/h average) and Berlin (8 km/h) are the calmest. Avoid Amsterdam and New York if wind is your weakness.
• Prefer predictability? Look at temperature standard deviation. Valencia (2.5°C) and Berlin (2.8°C) give you the narrowest range of likely conditions.

Whatever marathon you choose, Havik’s race analysis tools give you course-specific weather modeling, segment-level wind analysis, and pace adjustments tailored to actual forecast conditions — so you arrive at the start line with a plan built for the weather you will actually face.