370 Lakeside Triathlon
St. Peters, United States · August · Independent (MSE Racing)
Why people love it
- Flat, fast sprint and Olympic on country roads, with a park-trail run finish
- Beach start with wave starts and a clinic the day before
- Parking next to transition and finish, per a 2025 reviewer
- Organisers react to heat: extra aid stations, cold towels, half cancelled in 2025
Watch out for
- August heat above 30 °C (86 °F); the 2027 date moves to mid September
- Wetsuit rule and water temperature not published; lake likely above 27 °C (81 °F) in August
- Water quality is the lowest-scored category on Racecheck at 4.42 out of 5
- Only one aggregator source found; no blogs or forum reports surfaced
- Bike road closure status unknown
Race
How racers feel about it, how well it is run, and how it treats a first timer. Counts for 30% of the overall score.
Toughness: Moderate
- Racer satisfactionLoved4.3
Racecheck shows 52 reviews averaging 4.67 of 5 with almost no complaints. All come from one site, so held a little lower. · Medium confidence
- OrganizationFlawless4.5
Event logistics 4.83, staff 4.80 and finish area 4.85 on Racecheck; heat plan praised; pre-event communication lowest at 4.60. · Medium confidence
- First timer friendlyIdeal first race4.5
Super sprint and sprint pitched at newcomers; reviewers call it welcoming for first races and note a clinic the day before. · Medium confidence
Course traits, not part of the score
- PR potentialFast4.2
Organiser and reviewers call it flat and fast. No elevation or finish times are published. · Low confidence
Swim
Wetsuit odds, water temperature, calm, and the experience of the start. Counts for 16% of the overall score.
- Wetsuit legalSeldom1.6
Rule unpublished. USA Triathlon bans wetsuits above 28.8 °C (83.8 °F) for awards at 25.6 °C (78 °F); mid-August Missouri lakes usually exceed that. · Low confidence
- Water temperatureUncomfortable2.2
Likely 27 to 30 °C (81 to 86 °F) in August, above the 27 °C (81 °F) comfort limit; no published temperature. · Low confidence
- Calm waterMostly calm4.0
Inland park lake, no current reported. · Low confidence
- Swim easeEasy4.2
Beach start with waves and a lake; no current reported; wave start praised. · Medium confidence
- Swim experienceGreat3.7
Beach start and wave format liked; water quality is the lowest-scored Racecheck category at 4.42. · Low confidence
- Swim supportGood4.1
Wave starts, shallow beach start, open-water clinic the day before; support details not published. · Medium confidence
Bike
Road surface, closures, scenery and wind. Counts for 18% of the overall score.
- Road surfaceGood3.6
Country roads, not described in reviews. · Low confidence
- Road closuresPartly closed3.3
No source says whether the bike roads are closed. One reviewer noted low traffic on country roads. · Low confidence
- Bike sceneryPleasant3.4
Country roads in St. Charles County; reviewers rarely discuss scenery. · Low confidence
- WindSome wind3.0
Open farmland roads in the Midwest; no wind reports. · Low confidence
Course traits, not part of the score
- Bike speedFast4.2
Reviewers say fast and low traffic; surface not described. · Low confidence
- Bike flatnessMostly flat4.3
Described as flat and fast on country roads. Elevation gain is not published. · Low confidence
- Bike simplicityMostly simple4.0
Course described as easy to follow. · Low confidence
Run
Crowds, aid stations, conditions underfoot and scenery. Counts for 13% of the overall score.
- Crowd supportStrong3.5
Festival energy and lively atmosphere, per Racecheck summary. · Low confidence
- Aid stationsGood4.2
Extra aid stations and cold towels added in heat; volunteers praised. · Medium confidence
- Run sceneryBeautiful3.6
Lakeside park trails. · Low confidence
- Run conditionsModerate3.0
Trail surface is fine but August heat and humidity can hurt; cold towels and extra aid helped in 2025. · Low confidence
Course traits, not part of the score
- Run flatnessMostly flat4.3
Organiser says flat park trails; no figures. · Low confidence
Conditions
Air temperature, how predictable the weather is, setting, and spectating. Counts for 13% of the overall score.
- Air temperatureHarsh1.8
Typically 21 to 33 °C (70 to 91 °F) and humid; heat precautions needed in 2025. · Medium confidence
- Weather reliabilityVariable3.0
Heat and summer storms possible; half cancelled in 2025. · Low confidence
- Venue beautyLovely3.7
Suburban lake park with beach start; few reviews mention scenery. · Low confidence
- Spectator friendlyEasy4.0
Park venue with finish area and festival feel. · Low confidence
Course traits, not part of the score
- Low altitudeSea level4.8
About 150 m (490 ft) above sea level. · High confidence
Stay and travel
Hotels, walkability, getting there, and the town around the race. Counts for 10% of the overall score.
- Hotel availabilityGood4.3
St. Peters and the I-70 corridor have many chain hotels. · Low confidence
- Hotel valueGood3.8
Typical US suburban prices; no data. · Low confidence
- WalkabilityWalkable3.5
Parking next to transition and finish, per one reviewer. · Low confidence
- Travel easeEasy4.2
St. Louis Lambert about 35 km (22 mi) away. · Medium confidence
- LogisticsSimple4.2
Event logistics 4.83 on Racecheck; one venue; photo ID packet pickup. · Medium confidence
- Town and foodFine3.2
Suburban St. Charles County; thin evidence. · Low confidence
Key facts
- Location
- St. Peters, Missouri, United States
- Typical month
- August
- Latest or next date
- 12 September 2027
- Organiser
- Independent (MSE Racing)
- First held
- 2021
- Distances
- 1.5 km (0.9 mi) swim, 40 km (24.9 mi) bike, 10 km (6.2 mi) run
- Swim venue
- 370 Lakeside Park lake (lake)
- Swim start
- beach start, staggered waves (wave start praised in 2025 Racecheck review)
- Run shade
- not reported
- Air temperature
- 21–33 °C (70–91 °F)
- Humidity
- high
- Altitude
- 150 m (490 ft)
- Nearest airport
- St. Louis Lambert (STL), 35 km (22 mi) away
- Where to stay
- St. Peters, O'Fallon
- Booking
- St. Peters has chain hotels near I-70. Most athletes drive in from the St. Louis area.
What racers and reviewers say
- RacecheckRaced 2026 · aggregator · Positive
Racecheck shows 52 reviews averaging 4.67 out of 5 (2026 average 4.85), mostly 2025 and 2026, across super sprint, sprint, Olympic and half. Reviewers agree it is well run with smooth logistics, helpful staff and a flat, fast, easy-to-follow course. Several call it welcoming for first races and one praises parking next to finish and transition. Organisers earn credit for heat safety (extra aid, cold towels) and for cancelling the half in the 2025 heat. Weakest categories are water quality (4.42), swag and pre-event communication.
“Well organised event at a nice venue.”
Raced 370 Lakeside Triathlon? Your notes on the course, conditions and logistics help the next athlete decide.
Sources
Pages we used for facts and ratings. See how we rate.
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