Jenny Lake sits at the base of the Teton Range in Grand Teton National Park, Wyoming, at a recorded 2,073 metres. It is a glacially formed lake, smaller and more enclosed than Jackson Lake to its north, and held tight against the mountains along its western shore.
What drives the score here
Elevation is the thing to understand here. At just over 2,000 metres the water stays cold long into the season, and the Paddle Score cannot see it: no sensor measures this lake, so a bright summer day can score well over water cold enough to make a capsize serious. That surprises people every year. Being smaller and more sheltered than Jackson, Jenny is less often limited by wind, which makes the cold water, not the weather, its real constraint.
What the Paddle Score measures
A single number from 1 (Danger) to 5 (Excellent), built from wind speed and gusts, air temperature, UV index, cloud cover, precipitation and visibility at the lake — then constrained by fixed safety rules the model is not allowed to override. Wind above 25 mph costs two full points. Water temperature counts only where a sensor measures it, and none covers this lake yet, so judge cold water yourself. No score after dark, or while the lake is frozen or closed.
What the score can’t see
The mountains immediately west mean local wind can behave differently from the regional forecast the model reads. Treat the score as a starting point and look at the water before you commit.
Wear a life jacket, every time. The Paddle Score is a decision aid, not clearance to go out. It cannot account for your skill, your equipment, currents, traffic, or hazards at your launch site.