Weather & Water

Water temperature

Technical visualWater temperature
Water temperatureA thermometer is immersed below a waterline while the air remains a separate observation.WATERAIR
Water temperatureA thermometer is immersed below a waterline while the air remains a separate observation.121WATER2AIR

Use the measured water temperature for cold-water risk.

Water temperature and air temperature are separate observations; cold water can remain hazardous on a warm day.

Water temperature matters independently of air temperature.

Cold-water immersion can produce:

involuntary gasping

rapid breathing

loss of swimming performance

progressive hypothermia

Warm sunshine does not make cold water harmless.

Outrun should show temperature and relevant cold-water guidance rather than declaring a universal "safe" water temperature.

All Learn references