Lake
Les Trois Jetées
Les Trois Jetées water temperature is currently Cool. Cooler than it looks. Cold shock is possible on entry. Take your time getting in. Located in the North Temperate climate zone, it is currently spring. Air has averaged 12°C over recent weeks. The lake is still catching up. Refreshing conditions. Most swimmers will want a short wetsuit.
Last updated:
Cold
Cold water ahead. Cold shock is a real risk on entry. Limit your time in.
Air has averaged 12°C over recent weeks. The lake is still catching up. Refreshing conditions. Most swimmers will want a short wetsuit.
Lakes warm slowly in spring. Water is often colder than air conditions suggest.
Lake size
Larger lakes warm and cool slowly. Ponds respond quickly to air temperature.
Swum here recently?
Community temperature reports are the most reliable local data.
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7-Day Forecast
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9°C
High 10.7° / Low 8.1°
Cold conditions, a wetsuit is advisable
12.5°C
54cm depth
Ground holding warmth, stable water baseline
Weak
21 W/m²
Very little sunshine, minimal surface warming
4 km/h
S, gusts 5
Calm conditions, sheltered water likely
7.7°C
Feels like wet
Cool on exit. Get dressed quickly, especially in the wind.
24.7 mm
7-day total
25mm of rain in the last 7 days. Lake inflows may have cooled and clouded the water.
Model estimates. Always assess the water yourself before entering.
Frequently asked questions
How is the lake water temperature estimated?
Lake temperature is estimated using exponential smoothing of 60 days of air temperature data, based on Kettle et al. (2004). The algorithm accounts for lake thermal mass. Larger lakes respond more slowly to air temperature changes. This is not a direct measurement; accuracy is approximately plus or minus 2 to 3 degrees C.
What do the temperature categories mean?
Each category covers a 4 degree C band: Warm (20 degrees C or above, no wetsuit needed), Comfortable (16 to 20 degrees C, most swimmers fine), Cool (12 to 16 degrees C, wetsuit optional), Cold (8 to 12 degrees C, wetsuit recommended), Very Cold (4 to 8 degrees C, wetsuit essential), Ice Risk (below 4 degrees C, experienced swimmers only).
What is the geographic zone?
The zone is derived from the lake's latitude and altitude. It reflects the climate regime: temperate zones have the highest model accuracy; alpine and equatorial highland zones have reduced accuracy due to solar heating effects not fully captured by air temperature data alone.
What is the swimmer exit temperature?
The exit temperature uses the Steadman (1984) apparent temperature formula, which accounts for wind speed and humidity on wet skin. Exiting water in wind with wet skin causes significantly faster heat loss than the air temperature alone suggests, especially at speeds above 20 km/h.