Lake Sonoma 100k 2027
The forecast arrives five days before the start.
Here you'll find the elevation profile, an estimated finish time based on your UTMB Index and details of the 14 aid stations to plan your nutrition and hydration segment by segment.
What's your time based on your UTMB?
Times estimated by the RAVIT model, learned from real ultra-trail finish times. Enter your UTMB Index (utmb.world) to get a personalized estimate.
Cut-off times and crew - Lake Sonoma 100k · 2027
Data from the official race rules, checked for every edition. The race rules prevail. Positions are interpolated along the GPX track and are a guide, not official course marking.
What you'll find at each aid station
| Product | Pritchett Peakkm 9.3 | Woodbridgekm 18.2 | South Lake 1km 20.4 | Island View 1km 27.8 | Warm Springs 1km 39.0 | Wulfow 1km 47.0 | Liberty Glen 1km 51.7 | Lone Rockkm 58.7 | Liberty Glen 2km 65.7 | Wulfow 2km 70.4 | Warm Springs 2km 78.4 | Island View 2km 89.6 | South Lake 2km 97.0 | Finishkm 99.5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water | available | available | available | available | available | available | available | available | available | available | available | available | available | available |
| Brand products | unavailable | available | available | available | available | unavailable | available | available | available | unavailable | available | available | available | available |
La feuille de ton assistance pour Lake Sonoma 100k · 2027
Ton assistance peut te voir à ces postes. Ton plan RAVIT y met tes heures, ce qu'elle te tend et la route pour y aller.
- South Lake 1km 20.4
- Warm Springs 1km 39
- Liberty Glen 1km 51.7
- Liberty Glen 2km 65.7
- Warm Springs 2km 78.4
- South Lake 2km 97
Recto, verso et planche d'étiquettes, en PDF : l'exemple d'une coureuse de l'UTMB.
Elevation profile
The course and its aid stations
Lake Sonoma 100k: times, aid-station stops and fuelling needs by UTMB® Index
Between a UTMB® Index of 500 and 800, the estimated finish time on this race runs from 16h32 to 9h47, and the aid-station stop budget from 0h56 to 0h19. The longer the race, the more stops weigh: this is time you should plan to spend standing still, not only running.
Source
Below a UTMB® Index of roughly 420, the overall cut-off of 19h00 is no longer reachable at the estimated pace.
| UTMB® Index | Estimated time | Of which stops | Night hours | Carbs | Fluid | Sodium | Cut-off margin |
|---|---|---|---|---|---|---|---|
| 500 | 16h32 | 0h56 | 2.5 | 992 g | 11.6 L | 8,264 mg | +2h28 |
| 550 | 15h05 | 0h45 | 2 | 905 g | 10.6 L | 7,541 mg | +3h55 |
| 600 | 13h30 | 0h36 | 2 | 810 g | 9.4 L | 6,748 mg | +5h30 |
| 650 | 12h21 | 0h30 | 2 | 741 g | 8.6 L | 6,177 mg | +6h39 |
| 700 | 11h20 | 0h25 | 2 | 680 g | 7.9 L | 5,670 mg | +7h40 |
| 750 | 10h28 | 0h21 | 2 | 628 g | 7.3 L | 5,236 mg | +8h32 |
| 800 | 9h47 | 0h19 | 2 | 587 g | 6.8 L | 4,888 mg | +9h13 |
Figures based on 60 g of carbohydrate, 700 mL of fluid and 500 mg of sodium per hour, "average" preparation and mild conditions (15–25 °C). Above 25 °C, count on roughly 900 mL/h and 700 mg/h. Carbohydrate intake is trained: 60 g/h is a floor, 90 g/h assumes a glucose-fructose blend and a gut used to it.
In the 2027 ranking
Lake Sonoma 100k is 100 km and 3,242 m of elevation gain, that's 131 km-effort: category L, among 87 races in 2027. Its time limit of 19 h requires a minimum speed of 5.2 km/h: rank 65 out of 83 of the widest cut-off times in L.
L ultra-trails 2027: 115 to 154 km-effort
Similar effort in 2027
- Ultratril Fränkische Schweiz (UTFS) - Ultratrail (100km) · 131 km-effort
- Fjällmaraton 100k · 132 km-effort
- Waldo 100k · 132 km-effort
Other trails worth preparing for
- Javelina Jundred 100 miler158 km · 1,688 m D+ · October 31, 2026
- Javelina 100k97 km · 1,053 m D+ · October 31, 2026
- Tunnel Hill 5081 km · 182 m D+ · November 7, 2026
- Mountain Masochist 100k101 km · 3,268 m D+ · November 7, 2026
- Mountain Masochist 5081 km · 2,311 m D+ · November 7, 2026
- Looking Glass 100K98 km · 3,190 m D+ · November 14, 2026
- Pass Mountain 50 Mile81 km · 1,602 m D+ · November 14, 2026
- Jackson County Ultras100 km · 2,491 m D+ · December 5, 2026
- Devil Dog Ultra 100k100 km · 1,820 m D+ · December 5, 2026
Sources and method
- Time projection — times by UTMB Index are taken from the actual splits of runners in each level band on previous editions of this race, aid station stops included. No formula is used as long as these results exist.
- Trail nutrition — hourly targets for carbohydrate, fluid and sodium follow the commonly accepted ultra-endurance guidance. La Clinique du Coureur — Fuelling in trail running
- Course, aid stations and cut-offs — taken from the event's official rules, which prevail in case of any discrepancy. Official site — Lake Sonoma 100k
Weather for Lake Sonoma 100k
The weather for Lake Sonoma 100k will appear here as soon as the forecast models reach that date, around five days before the start: feels-like temperature, rain, snow, wind and storms, section by section and at your passage time.
Detailed weather for Lake Sonoma 100k, hour by hour on the courseFrequently asked questions
How many checkpoints?
Lake Sonoma 100k has 14 checkpoints: 11 aid stations and 3 water points. Details are in the two tables above.
What's the longest segment without aid?
The one leading to Warm Springs 1: 11.2 km and 333 m elevation gain. That's the one to load up for first.
How do I find the exact location of an aid station?
The Google Maps icon in the “Access” column opens the aid station's location: handy for planning your crew's routes.
What distance and elevation gain?
Lake Sonoma 100k is 100 km long with 3242 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 13h30 for Lake Sonoma 100k.
What's the weather forecast?
The weather for Lake Sonoma 100k will be published on this page around five days before the start, once the forecast models reach the race date. It will be detailed section by section: feels-like temperature, rain, snow, wind and storms.
Want to stack the odds in your favor for Lake Sonoma 100k?
In 2 minutes, RAVIT generates your complete plan: segment-by-segment time, carbs, water and sodium at every aid station, printable roadbook.
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