Don Juan Pond
Lake Extremely saline Antarctic pond remaining unfrozen year-round
A hypersaline pool in Antarctica’s McMurdo Dry Valleys, Don Juan Pond remains unfrozen under extreme salinity; scientists visit to study its unusual chemistry and implications for life in extreme environments.
Don Juan Pond is a very small, hypersaline lake located in Antarctica’s McMurdo Dry Valleys. It is notable for its exceptionally high salinity, which prevents the water from freezing even in extreme cold.
The pond’s brines are dominated by calcium chloride and remain liquid through Antarctic winters; the surface is shallow and the pond area varies seasonally. Its unusual chemistry and persistent liquid state make it important for scientific studies of saline ecosystems and perennially unfrozen water in polar environments.
Don Juan Pond is situated in the Wright Valley within the McMurdo Dry Valleys, an ice-free region of Antarctica on the continent’s coastline near the Ross Sea. The surrounding landscape is polar desert with exposed rock and minimal vegetation.
- Salinity: Extremely saline composition keeps the pond liquid at subzero air temperatures; its brines are dominated by calcium chloride.
- Scientific interest: Located in the McMurdo Dry Valleys, the pond is of strong scientific interest for studies of extreme environments and astrobiology.
How to Get to Don Juan Pond #
Visits are conducted as part of organized Antarctic field programs from research stations such as McMurdo; access requires coordination with national Antarctic programs and is limited to scientific teams and approved expeditions.
Tips for Visiting Don Juan Pond #
- Access requires coordination with national Antarctic programs-independent visits are not feasible.
- Carry appropriate cold-weather and field gear; Don Juan Pond is in one of the driest, coldest climates on Earth.
- Respect environmental guidelines set by Antarctic Treaty System and research authorities-no sampling without permits.
Best Time to Visit Don Juan Pond #
Best visited during the austral summer when research stations operate and logistics are possible; otherwise inaccessible.
Weather & Climate near Don Juan Pond #
Don Juan Pond's climate is classified as Ice Cap - Ice Cap climate with freezing summers (peaking in January) and freezing winters (coldest in August). Temperatures range from -34°C to -8°C. Very dry conditions with minimal rainfall with a pronounced dry season.
January
January is freezing with highs of -8°C and lows of -12°C. The driest month with just 1 mm.
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February
February is freezing with highs of -13°C and lows of -18°C. Almost no rain.
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March
March is freezing with highs of -21°C and lows of -26°C. Almost no rain and breezy conditions.
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April
April is freezing with highs of -25°C and lows of -30°C. Light rainfall and breezy conditions.
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May
May is freezing with highs of -26°C and lows of -32°C. Almost no rain.
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June
June is freezing with highs of -25°C and lows of -31°C. Light rainfall.
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July
July is freezing with highs of -27°C and lows of -32°C. Almost no rain and breezy conditions.
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August
August is the coldest month with highs of -27°C and lows of -34°C. Light rainfall and breezy conditions.
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September
September is freezing with highs of -25°C and lows of -31°C. Almost no rain and breezy conditions.
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October
October is freezing with highs of -22°C and lows of -27°C. Light rainfall and breezy conditions.
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November
November is freezing with highs of -14°C and lows of -18°C. Almost no rain and breezy conditions.
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December
December is freezing with highs of -8°C and lows of -12°C. Light rainfall.
