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Triathlon Atlas

Full distance · 12 September 2027

IRONMAN Wisconsin

Madison, United States

The race at a glance

Official race website
Circuit
IRONMAN
Distance
Full distance
Terrain
Road
Swim
3.8 km
Bike
180 km
Run
42.2 km
Date
12 Sept 2027
Registration
Open
Swim venue
Lake
Average water temperature
24 °C
Bike profile
Rolling
Bike elevation gain
1,702 m
Run profile
Hilly
Run elevation gain
231 m
High air temperature
28 °C
Low air temperature
12 °C
Overall cut-off
17 h
Entry fee, from
$810
Altitude
277 m
Swim start
Rolling start

Edition history

202613 Sept 2026Held
20257 Sept 2025Held
20248 Sept 2024Held
202310 Sept 2023Held
202211 Sept 2022Held
202112 Sept 2021Held
20198 Sept 2019Held
20189 Sept 2018Held
201710 Sept 2017Held
201611 Sept 2016Held

How the day is laid out

The swim is held in a lake. The wetsuit call is made on race morning, against the temperature measured then.

The organiser publishes 3.8 km of swimming, 180 km on the bike and 42.2 km of running.

The swim uses a rolling start: athletes enter the water a few at a time. The water is usually around 24 °C at this time of year.

The bike course is rolling, with about 1,702 m of climbing.

The run course is hilly, with about 231 m of climbing.

Typical temperatures for the month run from 12 to 28 °C. The overall cut-off is 17 hours.

Readings below the average

The race banner on ironman.com gives an average water temperature of 24 °C. The readings published for the last three editions in Lake Monona were lower: 21 °C (70 °F) in 2024, 19 °C (67 °F) in 2025 and 23 °C (74 °F) in 2026, all under the 24.5 °C wetsuit limit for age-group athletes.

The swim uses a self-seeded rolling start. Athletes run up the Helix out of the water and ride down it at the start of the bike, before a rolling two-lap course through farmland and Verona.

Source: ironman.com, read on 21 October 2026. The IRONMAN in the USA page compares it with the other US races.

Against the calendar

Where this race sits among the others

Ranks are computed across every race of the same distance.

  • Average water temperature

    24 °C · median 22 °C

    The 13th warmest of the 48 full-distance races with a figure, across every circuit.

  • High air temperature

    28 °C · median 25 °C

    The 15th hottest of the 52 full-distance races with a figure, across every circuit.

  • Bike elevation gain

    1702 m · median 1130 m

    The 13th hilliest of the 43 full-distance races with a figure, across every circuit.

1

races of this distance pair a rolling bike with a hilly run, out of 55. 20 share the bike profile alone.

45

races across every distance fall in September, out of 354.

68

races are held in North America. 11 of them in the same month as this one.

Questions about this race

When is IRONMAN Wisconsin 2027?
IRONMAN Wisconsin is held on 12 September 2027 in Madison, United States. Registration is open on the official race page.
Is a wetsuit allowed at IRONMAN Wisconsin?
Most likely. The average water temperature is 24 °C, below the 24.5 °C limit up to which wetsuits are allowed for age-group athletes. The official call is made on race morning.
What is the cut-off at IRONMAN Wisconsin?
The course closes 17 h after the start. Intermediate cut-offs after the swim and the bike are in the athlete guide.
How hard is IRONMAN Wisconsin?
The bike course climbs about 1702 m, the 13th hilliest of 43 full-distance races with a figure. The bike is labelled rolling and the run hilly. Expect highs of about 28 °C on race day.
How much is the entry fee for IRONMAN Wisconsin?
Entries start at US$810 for an individual age-group entry, before service fees. Prices rise by tier as the race fills.

Where to stay

Hotels and rentals around the race venue, for the nights around race day.

Suggested stay: 10 Sept 2027 to 13 Sept 2027

The map is provided by Stay22. Bookings are made with the provider.

Races of the same distance in the same region

Entries are handled by the organiser

Registration and the athlete guide are on the official race page.

Open the official race page