the running cat.
Race data

The 10 Fastest Half Marathons in Europe for 2027, Ranked by Weather Data

Course profiles, race-day weather and trip budgets, plus two famous races where my results disagree

10 races · 3 years of race-week weather
Photo by Miguel A Amutio on Unsplash

Let it rain!

My best half marathon ever happened in 14°C and steady rain in Valencia. I ran a negative split and finished in 1:42:05, 2 minutes and 40 seconds faster than a PB that had resisted me for three years. A few months earlier, in Prague, I had trained just as hard, but the sun was out. At km 7 I let the 1:45 pacers go, and I crossed the line in 1:50.

Same runner, same training, very different results. That’s why I started digging into weather data and wrote two articles about how much the sun slows you down. Long story short: the shade temperature in the forecast doesn’t tell you what you’ll feel on the course.

Since then, I’ve kept collecting race data. In fact, I went a bit further and built a small website around it. It’s called EuroSlam, a free calendar of marathons and half marathons across Europe. To be honest, it started as a spreadsheet to answer my own question: where should I run my next PB?

Every race on it gets a speed score from 1 to 10, based on the course profile and typical race-day conditions. I also track elevation gain, entry fee, field size, the average race-week weather over the last three years, and a rough trip budget (entry, hotel and travel).

Here are the ten highest-scoring half marathons for the 2027 season, in race order. Where I’ve run the race myself, I’ll tell you if the data and my legs agree.

Entry fees and dates change, so always check the organiser’s site before booking.

1. Barcelona Half Marathon, Spain: Sun 14 Feb 2027

Speed score 8/10 · +30 m · 16°C high / 8°C low · rain chance 24%

A flat seafront course from Plaça de les Glòries through the Olympic Village and along the waterfront. Mid-February in Barcelona is about as close to perfect running weather as you’ll find in winter, and it’s a nice way to escape the cold for a weekend.

2. Lisbon Half Marathon, Portugal: Sun 7 Mar 2027

Speed score 9/10 · +125 m · 15°C high / 10°C low · rain chance 52%

Here’s my first disagreement with my own data. On paper, Lisbon is great: it’s marketed as one of the fastest half marathons in the world, you start on the 25 de Abril bridge over the Tagus, and the March averages look cool.

I ran it in 2024 and finished in 1:46:46. Until km 11 I felt great. After that, the sun came out along the river, and the second half was a fight. The professionals barely notice it, but as a recreational runner, I did. If the forecast says clear skies, adjust your goal.

3. Berlin Half Marathon, Germany: Sun 4 Apr 2027

Speed score 9/10 · +20 m · 15°C high / 5°C low · rain chance 24%

Europe’s largest half marathon: 48,000 runners on one of the flattest courses in the world, from Mitte through the Tiergarten and back past the Brandenburg Gate. I ran it in 2023 and had ideal conditions. If I could pick only one spring race for a PB, it would be this one.

4. Semi de Paris, France: Sun 4 Apr 2027

Speed score 8/10 · +50 m · 17°C high / 8°C low · rain chance 48%

One of the biggest half marathons in the world, from the Hôtel de Ville to the Bois de Vincennes. The data rates it well, but I’ll be honest: I ran Paris, and although it’s one of the best-organised races I’ve ever done, I didn’t find it a PB race.

5. London Landmarks Half Marathon, UK: Sun 4 Apr 2027

Speed score 8/10 · +40 m · 16°C high / 8°C low · rain chance 24%

The only closed-road half marathon through the heart of London, past Big Ben, the Tower of London, St Paul’s and Buckingham Palace. It’s more of a sightseeing tour than a time trial, but the course is flat enough for a good result.

6. Warsaw Half Marathon, Poland: Sun 4 Apr 2027

Speed score 8/10 · +30 m · 14°C high / 4°C low · rain chance 38%

Poland’s biggest road race, almost entirely flat, along the Vistula and through Łazienki Park. It has the coldest mornings on this list and the cheapest weekend: just €40 to enter.

Did you notice? Four of my top ten are on the same Sunday, 4 April 2027. Prague runs the day before. You’ll have to choose, so choose by the forecast.

7. Vienna Half Marathon, Austria: Sun 18 Apr 2027

Speed score 8/10 · +60 m · 17°C high / 8°C low · rain chance 48%

The half runs alongside the Vienna City Marathon, past the Prater, the Ringstrasse and the State Opera. It’s a fast, flat course on a big-city weekend, two weeks after the 4 April crowd.

8. Riga Half Marathon, Latvia: Sun 16 May 2027

Speed score 8/10 · +30 m · 16°C high / 7°C low · rain chance 52%

Flat and fast through the Art Nouveau streets of Riga, past the Freedom Monument and along the Daugava. It’s small, cheap and cool in mid-May, a good late-spring option if you missed your April goal.

9. Copenhagen Half Marathon, Denmark: Sun 19 Sep 2027

Speed score 9/10 · +20 m · 18°C high / 13°C low · rain chance 19%

My second disagreement. The course is the flattest in Scandinavia, and it hosted the 2026 World Athletics Road Running Championships. But I ran it in 2023, and I can honestly say it felt hot. When I looked at the weather data for my SuperHalfs article, Copenhagen was the race getting warmer year after year. It was last in my personal ranking.

If you go, look at the cloud cover the week before. With overcast skies, it’s a PB course. With sun, enjoy the race and smile.

10. Cardiff Half Marathon, UK: Sun 3 Oct 2027

Speed score 8/10 · 17°C high / 10°C low · rain chance 43%

Here the data and I agree. I ran Cardiff in 2023 with cloudy skies, light rain and high humidity, and finished in 1:45:34, my season’s best. Cardiff rarely surprises with the weather: you can almost always expect overcast skies. The course has a few bends and isn’t the fastest on paper, but the conditions make up for it.

Close, but not quite

My quick picks

How I built this list

All the numbers come from the race pages on EuroSlam:

One lesson from my heat articles still applies: these are shade temperatures. A sunny 15°C can feel like 20°C or more in the second half. Check the cloud cover and the solar radiation in the forecast the week before, then decide whether it’s a PB day or a day to enjoy the race.

And, as always, I book my hotel within 2–3 km of the start so I can jog there as my warm-up.

If you’d like to see the weather, hotels near the start and the trip budget for any of these races, they’re all on my website. It also has a free passport: one medal for each European country you’ve run a half or full marathon in. This list alone covers nine countries.

Browse all half marathons in Europe

(EuroSlam is my own free side project. Some hotel links on the site earn me a small commission, at no extra cost to you.)

If you’d like to read more about weather and racing, here’s the article where I compared the six SuperHalfs:

Which SuperHalfs Half Marathon Series Offers the Best Weather?

Which of these are you running next? Tell me in the comments 👇

Good luck, and see you on the course!

I'm a recreational runner with an office job, testing running science on my own legs. More about me.