IRONMAN Portugal-Cascais
Cascais, Portugal · October · IRONMAN
Why people love it
- Scenic semi-sheltered bay swim with a rolling start
- Fully closed roads from Cascais to Guincho (07:00 to 02:00)
- Bike through Sintra-Cascais Natural Park and the Estoril circuit
- Lisbon airport 30 km (19 mi) away with cheap flights
- Strong finish atmosphere in Cascais
Watch out for
- Cool 16-19 °C (61-66 °F) water, with a possible strong return current or swell
- Atlantic wind at Guincho and about 1,400-1,556 m (4,600-5,100 ft) of bike climbing
- Course changes year to year (2023 swim, 2024 bike)
- Much of the field finishes in darkness; sold out in 2026, so book early
- Some evidence comes from the 70.3 on the same roads
Race
How racers feel about it, how well it is run, and how it treats a first timer. Counts for 27% of the overall score.
- Racer satisfactionLoved4.2
Athletes praise the bay, finish atmosphere and organisation (one gave 8/10, another called it worth it). Complaints are mostly weather and course changes. · Medium confidence
- OrganizationWell run3.7
Strong municipal support and closures, offset by a last-minute swim reroute in 2023 and a 2024 bike change with an unsafe switchback. · Medium confidence
- First timer friendlyDoable2.9
Logistics are easy, but expect 1,500 m (4,920 ft) of bike gain, Atlantic wind, a return-leg swim current and a dark finish for many. · Medium confidence
Course traits, not part of the score
- PR potentialAverage2.8
The median finish was 12:05 across 2021-2025. The bike climbs 1,400-1,556 m (4,600-5,100 ft), Guincho is windy and the run rolls. · Medium confidence
- Course easeVery tough2.4
Bike gain of 1,400-1,556 m (4,600-5,100 ft) plus 189-325 m (620-1,066 ft) on the run, with wind, cool water and darkness. · Medium confidence
Swim
Wetsuit odds, water temperature, calm, and the experience of the start. Counts for 15% of the overall score.
- Wetsuit legalAlmost always4.9
Water is typically 16-19 °C (61-66 °F), well under the 24.5 °C (76.1 °F) age-group limit. · Medium confidence
- Water temperatureAcceptable3.3
Typically 17-19 °C (63-66 °F), and 16-17 °C (61-63 °F) in 2025. That is cooler than the comfortable 19-23 °C (66-73 °F) range. · Medium confidence
- Calm waterSome chop3.1
A semi-sheltered bay, but 2023 swell forced a reroute and tide plus swell produced a strong return current in 2025. · Medium confidence
- Swim easeModerate3.0
A single lap with a chaotic turn and a strong return-leg current, but otherwise clear and easy to sight. · Medium confidence
- Swim experienceGreat4.1
A semi-sheltered bay with clear water, a rolling start and a spectacular setting. Expect some jellyfish and a chaotic turn. · Medium confidence
Bike
Road surface, closures, scenery and wind. Counts for 19% of the overall score.
- Road surfaceGood3.6
A mix of coastal and park roads, with no major complaints found. · Low confidence
- Road closuresMostly closed4.4
Time Out lists total closures from Cascais to Guincho from 07:00 to 02:00, plus the Estoril circuit. · Medium confidence
- Bike sceneryBeautiful4.4
Atlantic coast, Guincho dunes, Sintra-Cascais Natural Park and the Estoril circuit. · High confidence
- WindWindy2.3
Atlantic wind at exposed Guincho is the repeated warning. · Medium confidence
Course traits, not part of the score
- Bike speedAverage3.0
A flat, fast first section (packed with drafting at the 70.3), then the Sintra and Guincho climbs. Moderately paced overall. · Medium confidence
- Bike flatnessRolling2.9
Bike climbing is 1,400-1,556 m (4,600-5,100 ft) over 180 km (112 mi), which is hilly. · Medium confidence
- Bike simplicitySome technical parts2.6
A steep switchback climb was judged unsafe in 2023, and the course includes the Estoril circuit and park descents. · Medium confidence
Run
Crowds, aid stations, conditions underfoot and scenery. Counts for 13% of the overall score.
- Crowd supportStrong3.9
A strong finish crowd, with spectators lining the bike route and run. · Medium confidence
- Aid stationsGood3.6
Athletes reported good aid on the bike and run at the 70.3, but toilets and showers were short. · Low confidence
- Run sceneryBeautiful4.2
Seafront promenade and marina with a sea breeze. · Medium confidence
- Run conditionsModerate3.1
Cool, sea-breezed and aid-rich, but with little shade, and much of the field finishes in darkness. · Medium confidence
Course traits, not part of the score
- Run flatnessRolling3.0
Three loops with 189-325 m (620-1,066 ft) of gain and false flats. One reporter called the loops hilly. · Medium confidence
Conditions
Air temperature, how predictable the weather is, setting, and spectating. Counts for 15% of the overall score.
- Air temperaturePleasant4.4
Race-day air is 16-24 °C (61-75 °F), and 20-23 °C (68-73 °F) with drizzle in 2025. · Medium confidence
- Weather reliabilityVariable2.7
October brought race-week storms and swell in 2023 and drizzle in 2025, yet the 70.3 reached 27-29 °C (81-84 °F). · Medium confidence
- Venue beautyStunning4.5
Cascais bay and marina with Atlantic cliffs. · High confidence
- Spectator friendlyEasy4.1
The three-loop run and two-loop bike pass the centre repeatedly. · Medium confidence
Course traits, not part of the score
- Low altitudeSea level5.0
Sea level. · High confidence
Stay and travel
Hotels, walkability, getting there, and the town around the race. Counts for 11% of the overall score.
- Hotel availabilityBook early3.0
The race sold out for 2026, but apartments are widely available near Cascais. · Low confidence
- Hotel valueNormal2.8
Official hotel packages started from about EUR 253 (about US$275) a night in 2025. · Low confidence
- WalkabilityWalkable3.8
Apartments by transition are easy, while the official hotel is about 5 km (3 mi) out with shuttles. · Medium confidence
- Travel easeVery easy4.6
Lisbon airport is about 30 km (19 mi) away, with cheap flights and a 40-minute taxi. · High confidence
- LogisticsSome complexity3.2
A compact base, but yearly course changes and reports of unclear 70.3 logistics. · Medium confidence
- Town and foodGood4.4
Cascais old town and seafood, with Lisbon nearby. · Medium confidence
Key facts
- Location
- Cascais, Lisbon District, Portugal
- Typical month
- October
- Latest or next date
- 17 October 2026
- Organiser
- IRONMAN
- Field size
- About 1,500 athletes
- Entry fee
- About $790
- First held
- 2021
- Distances
- 3.8 km (2.4 mi) swim, 180 km (112 mi) bike, 42.2 km (26.2 mi) run
- Cutoffs
- Swim 2:20, Bike 10:30, Finish 17:00
- Swim venue
- Bay of Cascais (start Praia da Ribeira, exit at Fortaleza/Club Naval) (ocean)
- Water temperature
- 17–19 °C (63–66 °F)
- Wetsuit
- Legal
- Swim start
- rolling
- Swim laps
- 1
- Bike climbing
- 1,500 m (4,920 ft)
- Bike laps
- 2
- Key climbs
- Guincho to Natural Park climb (~10 km, gentle with some steeper parts); Malveira da Serra / Alcabideche section; Estoril circuit
- Run climbing
- 250 m (820 ft)
- Run laps
- 3
- Run shade
- Little shade on coast road; sea breeze; finish in darkness for much of field
- Air temperature
- 16–24 °C (61–75 °F)
- Humidity
- Moderate, coastal
- Altitude
- 0 m (0 ft)
- Nearest airport
- Lisbon (LIS), 30 km (19 mi) away
- Where to stay
- Cascais centre, Marina de Cascais, Estoril
- Booking
- Official hotel Quinta da Marinha (about 5 km from centre, shuttles, packages from about 253 EUR in 2025). Apartments near Cascais widely available. Car hire not necessarily convenient given closures; train/taxi options.
What racers and reviewers say
- Olí Le TriathleteRaced 2025 · blog · Positive
Finished 11:57 six months after a broken collarbone. Swim was comfortable until a strong current on the return. Bike was hilly but enjoyable; run was three hilly loops with fuelling going haywire. Praised organization and the finish crowd, rated overall 8/10.
“From broken collarbone to IronMan finisher in less than six months.”
- Iron LenRaced 2023 · blog · Mixed
Race-week storms and a last-minute swim route move into bigger swell and a turned tide. Bike had a route change adding a steep switchback climb he found unsafe, with a crash. Stomach problems wrecked the run; apartment stay near Cascais was fine.
- RaceRavesRaced 2022 · aggregator · Positive
First-timer praised the town, atmosphere and Atlantic swim. Described bike as two loops with a steep climb in the park plus a long coastal stretch, and a three-loop run with false flats. Scored scenery 5, difficulty 4, production 3.
- Iron Len (70.3)Raced 2025 · blog · Positive
70.3 on the same course in warm 27–29 °C (81–84 °F) weather. Swim turn chaotic, Guincho climb about 10 km (6.2 mi) with some steep bits, rolling run, showers and aid helped. Spectators lined the finish and bike route; rented apartment by transition.
“Not something I like and find very tough to deal with.”
- Outsider.ie (Jamie Ball)Raced 2025 · article · Positive
70.3 write-up praising calm rolling-start swim, closed roads and good aid on the 90 km (56 mi) bike, and supportive crowds on the run. Stayed at official hotel Quinta da Marinha with shuttles and pasta party. Recommends arriving two days early; cheap flights from Dublin.
“Overall, was it worth doing? Most certainly.”
Show 6 more
- RaceCheck (Helen V.)Raced 2019 · aggregator · Positive
70.3 reviewer loved the stunning location and easy access from Lisbon. First 25 km (16 mi) of bike flat but packed with drafting; later section hilly. Run hilly and hard in heat with few toilets and showers; logistics unclear.
- Slowtwitch (Herbert Krabel)article · Positive
Preview of the 70.3 course on the same roads, calling the bay one of the most spectacular in Portugal. Route follows the ocean to Oeiras then through Sintra forests and back via Guincho; run along the seafront promenade with a cooling sea breeze.
- Race-Mindaggregator · Positive
Describes a sheltered bay with 17–19 °C (63–66 °F) water and possible jellyfish, a fast Riviera bike through the Estoril circuit, and a coastal run with many spectators. Warns of strong Atlantic wind at Guincho; entry sold out at 680 EUR.
- KeirolabsRaced 2025 · aggregator · Mixed
Data-driven guide: 1,556 m (5,105 ft) bike gain, 189 m (620 ft) run gain, cutoffs 2:20/10:30/17:00, median finish 12:05 over 2021-2025 and 9% DNF-ish attrition. Notes most of the field runs the closing laps in the dark, requiring a light.
- Time Out CascaisRaced 2025 · article · Positive
Local article on 2025 race listing extensive road closures from Cascais to Guincho (all day into the night) and the Estoril circuit, with the 8:40 sunrise start at Praia da Ribeira. Shows strong municipal support and complete closures.
- Finishers.comaggregator · Mixed
Lists two-loop 180 km (112 mi) bike with 1,400 m (4,593 ft) gain and a three-loop 42.2 km (26.2 mi) run with 325 m (1,066 ft) gain; total about 1,725 m (5,659 ft).
Sources
Pages we used for facts and ratings. See how we rate.
Training for IRONMAN Portugal-Cascais? Moku Coach builds your plan around race day.