Expected race conditions

Locations

Every location page gets the same profile: the water record, water and air temperature, daylight, trail conditions and the town calendar. No numbers are published for a location until they have been collected from the record.

Durango, Colorado — the full profile

Host of the 2027 race, September 18. Everything below is drawn from the published record for that week of the year.

The short version

The river

The river paddle is the leg with the least tolerance, so it is the one we studied hardest. The gauge that matters sits in our town run and carries 127 years of record — long enough that these are odds, not guesses.

Around September 18 the typical flow is 326 cfs, with the middle half of all years landing between roughly 250 and 450. Commercial rafting companies run this same stretch all September at 250 to 600. About nine years in ten deliver at least 200.

What we actually raced on

This is not theoretical. These are the flows on that week of the year in each of our Durango race years — we ran the river paddle at exactly these levels three years straight:

The risk we are actually carrying

It is the one-in-ten deep-drought year. In 2018 the river bottomed out near 107 cfs. If 2027 turns out that way, the paddle moves to the lake — a published fallback with decision points set well in advance, not a race-week scramble.

Water temperature

The river sits around 59 degrees in mid-September, ranging 56 to 63 across the last decade of records. That is cold-water territory, and the water legs are run accordingly — our water-safety lead sets the actual requirements, and they are published with the race rules.

The lake runs warmer, in the upper 60s in late summer, and sanctioned triathlon swims are held there in early-to-mid September. The swim window is proven. We run our own water-safety operation on race day regardless, because the river requires one.

Weather

Normals for the date are a 76-degree afternoon and 42 at dawn. Cold mornings for wet athletes, and manageable. The monsoon is fading by mid-September but it is still the wettest month of the fall, so short rain spikes are something we watch rather than something that surprises us.

Daylight

Daylight runs sunrise at 6:56 to sunset at 7:15, with workable light to roughly 7:41 — about thirteen hours, less twenty to forty-five minutes at each end where the terrain shades the valley. Every cutoff is derived from that specific sunset. A 92 percent moon comes up at 8:20 for teardown.

Trail conditions

The trails around Durango are at their best in mid-September. The monsoon has done the watering, the dust is down, the temperatures are moderate, and the early-summer fire-smoke season is well behind us.

In town that weekend

Race weekend shares the town with the Autumn Arts Festival, which runs downtown from Friday evening through Sunday. The course does not need those blocks — but lodging fills early on a festival weekend, so book rooms as soon as your team commits. It also means the people travelling with you have something to do while you race.

Everything on this page is historical record and published odds, not a forecast. We re-check the river at set points through the year — the winter snowpack reading, the spring runoff forecast, then race week off the live gauge — and the fallback is published in advance so nobody is guessing about it late.