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Wales · United Kingdom

Bala Lake Water Temperature Today

Bala Lake in Wales, United Kingdom is swimmable in high summer, brisk either side of it, and drops close to single digits in winter.

In August Bala Lake averages about 19°C at the surface, peaking near 19°C in July, August, September and dropping to roughly 5°C at its coldest.

Water temperature estimate
19.0°Cmild
August climatology for this lake · Good
Typical in August
19.0°C
Air temperature
Wind
UV index

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.

Bala Lake water temperature by month

MonthAverage water temperatureSwimming
January5.9°Ccold
February5.0°Ccold
March5.9°Ccold
April8.5°Ccold
May12.0°Ccool
June15.5°Cmild
July18.1°Cmild
August19.0°Cmild
September18.1°Cmild
October15.5°Cmild
November12.0°Ccool
December8.5°Ccold

Bala Lake swim conditions FAQ

Best time to swim, water safety and the temperature thresholds that matter for open-water swimming in Bala Lake.

Best time to swim

The warmest water in Bala Lake is in July, August, September, around 19.0°C.

The comfortable swim season — 18°C or warmer — covers July, August, September. Right now (August) expect about 19.0°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 Bala Lake 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

WaterFeelsWhat to do
24°C and aboveWarmComfortable for long swims in swimwear. Watch UV and stay hydrated.
20–23°CPleasantIdeal open-water conditions for most swimmers; no neoprene needed.
18–19°CFreshFine for 30–60 minutes; a shorty wetsuit extends comfort.
14–17°CCoolCold-water rules apply. A 3/2mm full suit is sensible.
10–13°CColdLimit to short swims, 4/3mm suit, gloves and boots; never swim alone.
Below 10°CVery coldCold shock and swim failure risk. Acclimatised swimmers only, minutes not hours, with supervision.

At today's estimate of 19.0°C, Bala Lake rates as mildGood.

What is the water temperature of Bala Lake right now?

In August the surface of Bala Lake averages about 19°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 Bala Lake?

Yes. Bala Lake 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 Bala Lake?

July, August, September offer the warmest water, around 19°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 Bala Lake get in winter?

The coldest month averages roughly 5°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 Bala Lake?

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. Bala Lake peaks near 19°C and bottoms out near 5°C.

Is Bala Lake 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.

Warmest today
Bala Lake · 19.0°C
Bala LakeLake VyrnwyLlyn Brenig
LakeTodayNext 7 days
Bala LakeUnited Kingdom19.0°CmildLoading forecast…
Lake VyrnwyUnited Kingdom18.0°CmildLoading forecast…
Llyn BrenigUnited Kingdom17.0°CmildLoading 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.

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