Lac de Pierre-Percee Water Temperature Today
Lac de Pierre-Percee in Grand Est, France reaches comfortable swimming temperatures in July and August, and drops close to single digits in winter.
In August Lac de Pierre-Percee averages about 22°C at the surface, peaking near 22°C in July, August, September and dropping to roughly 4°C at its coldest.
Lake surface temperatures are modelled from long-term monthly averages and refined with live air temperature, wind and UV. Sea temperatures elsewhere on SwimTemperature come from measured marine model data.
Lac de Pierre-Percee water temperature by month
| Month | Average water temperature | Swimming |
|---|---|---|
| January | 5.2°C | cold |
| February | 4.0°C | cold |
| March | 5.2°C | cold |
| April | 8.5°C | cold |
| May | 13.0°C | cool |
| June | 17.5°C | mild |
| July | 20.8°C | warm |
| August | 22.0°C | warm |
| September | 20.8°C | warm |
| October | 17.5°C | mild |
| November | 13.0°C | cool |
| December | 8.5°C | cold |
Lac de Pierre-Percee swim conditions FAQ
Best time to swim, water safety and the temperature thresholds that matter for open-water swimming in Lac de Pierre-Percee.
Best time to swim
The warmest water in Lac de Pierre-Percee is in July, August, September, around 22.0°C.
The comfortable swim season — 18°C or warmer — covers July, August, September. Right now (August) expect about 22.0°C.
Within a day, the surface is warmest in the late afternoon, while early morning is calmest and quietest for boat traffic.
Water safety tips
- Enter Lac de Pierre-Percee slowly and let your breathing settle before swimming out — cold shock is the biggest single risk in fresh water.
- Swim parallel to the shore rather than out and back, so you are never far from a safe exit.
- Lakes have no lifeguard on most shorelines: swim with a partner and use a bright tow float so boats can see you.
- Check for boat traffic, sudden drop-offs, weed beds and submerged obstacles before your first swim of the season.
- Deep lakes stay cold below the surface even in a heatwave — expect a sharp thermocline a metre or two down.
- After heavy rain or during a warm calm spell, avoid swallowing water: runoff and algal blooms can cause illness.
- Get warm and dressed quickly after cold swims — afterdrop peaks 10–30 minutes out of the water.
Temperature thresholds
| Water | Feels | What to do |
|---|---|---|
| 24°C and above | Warm | Comfortable for long swims in swimwear. Watch UV and stay hydrated. |
| 20–23°C | Pleasant | Ideal open-water conditions for most swimmers; no neoprene needed. |
| 18–19°C | Fresh | Fine for 30–60 minutes; a shorty wetsuit extends comfort. |
| 14–17°C | Cool | Cold-water rules apply. A 3/2mm full suit is sensible. |
| 10–13°C | Cold | Limit to short swims, 4/3mm suit, gloves and boots; never swim alone. |
| Below 10°C | Very cold | Cold shock and swim failure risk. Acclimatised swimmers only, minutes not hours, with supervision. |
At today's estimate of 22.0°C, Lac de Pierre-Percee rates as warm — Excellent.
What is the water temperature of Lac de Pierre-Percee right now?
In August the surface of Lac de Pierre-Percee averages about 22°C. The reading at the top of this page refines that monthly average with today's live air temperature, wind and UV.
Can you swim in Lac de Pierre-Percee?
Yes. Lac de Pierre-Percee reaches 18°C or warmer in July, August, September, which most swimmers find comfortable without neoprene. Outside those months treat it as cold-water swimming.
When is the best time to swim in Lac de Pierre-Percee?
July, August, September offer the warmest water, around 22°C. Within the day, late afternoon is usually warmest at the surface, while early morning is calmest with the least boat traffic — the usable swim season runs across July, August, September.
How cold does Lac de Pierre-Percee get in winter?
The coldest month averages roughly 4°C at the surface. At that temperature cold shock is a genuine hazard for unacclimatised swimmers.
What water temperature is safe to swim in?
Above 20°C is comfortable for most people, 18–20°C is fresh but fine for shorter swims, 14–17°C calls for a wetsuit, and below 10°C is experienced cold-water swimmers only — minutes rather than hours, always with someone watching.
Do I need a wetsuit in Lac de Pierre-Percee?
Based on the monthly averages: no wetsuit needed at 22°C or above, a shorty from about 18°C, a 3/2mm full suit from 14°C, and 4/3mm with gloves and boots below 14°C. Lac de Pierre-Percee peaks near 22°C and bottoms out near 4°C.
Is Lac de Pierre-Percee safe to swim in?
Most of the year, yes, provided you pick a known entry point, swim parallel to the shore with a partner, and check local signage. Avoid swimming after heavy rain or during visible algal blooms, and remember lake shorelines are rarely lifeguarded.
Compare lake temperatures
Pick up to 4 lakes to compare today's water temperature and the next seven days.
| Lake | Today | Next 7 days |
|---|---|---|
| Lac de Pierre-PerceeFrance | 22.0°Cwarm | Loading forecast… |
| Lac de GerardmerFrance | 22.0°Cwarm | Loading forecast… |
| Lac de MadineFrance | 23.0°Cwarm | Loading forecast… |
Water temperatures are modelled from long-term monthly averages for each lake and refined daily with forecast air temperature, so the seven-day column shows the expected trend rather than a measured buoy reading.
Open the full lake comparison tool · See Lac de Pierre-Percee on the live lake temperature map
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